ON-BOARD DIAGNOSTICS ME7.2 Engine Management

ON-BOARD DIAGNOSTICS ME7.2 Engine Management Vehicle Coverage: New Range Rover 2005 MY Land Rover Revision Date: September 2004 Page 1 of 84

1 Contents 1 Contents 2 2 Introduction 5 2.1 Inputs and Outputs 5 3 Mode $06 Data 7 4 OBD Drive Cycle Information 10 5 On Board Monitoring 12 5.1 Catalyst Monitoring 12 5.1.1 Description 12 5.1.2 Monitoring Structure 13 5.1.3 Block Diagram of System Operation 15 5.1.4 Drive Cycle Information 16 5.2 Misfire Monitoring 17 5.2.1 Description 17 5.2.2 Monitoring Structure 18 5.2.3 Fault Processing for Emissions Relevant Misfire 21 5.2.4 Drive Cycle Information 22 5.3 Secondary Air Injection System Monitoring 23 5.3.1 Description 23 Monitoring Structure 24 5.3.3 Drive Cycle Information 25 5.4 Evaporative Emission System Leak Measurement 26 5.4.1 Description of Leak Measurement 26 Monitoring Structure 29 5.4.3 Description of Evaporative Emission Canister Purge System Flow Check 34 5.4.4 Monitoring Structure 34 5.4.5 Drive Cycle Information 39 5.5 Fuel System Monitoring 40 5.5.1 Description 40 Monitoring Structure 42 5.5.3 Drive Cycle Information 44 5.6 Oxygen Sensor Monitoring 45 5.6.1 Description 45 Monitoring Structure 46 5.6.3 Oxygen Sensor Heater Monitoring Description 48 5.6.4 Oxygen Sensor Heater Monitoring Structure 49 5.6.5 Drive Cycle Information 53 5.7 Thermostat Monitoring 55 Description 55 Monitoring Structure 56 Land Rover Revision Date: September 2004 Page 2 of 84

5.7.3 Drive Cycle Information 59 5.8 Positive Crankcase Ventilation (PCV) System Monitoring 60 5.8.1 Description 60 5.8.2 Drive Cycle Information 62 5.9 Crankshaft Speed and Position Sensor 63 5.9.1 Description 63 5.9.2 Drive Cycle Information 63 5.10 Camshaft Position Control Interface (VANOS) 64 5.10.1 Description 64 5.10.2 Drive Cycle Information 65 5.11 Engine Coolant Temperature Sensor 66 5.11.1 Description 66 5.11.2 Drive Cycle Information 67 5.13 Mass Airflow Sensor & Intake Air Temperature Sensor 68 5.13.1 Mass Airflow Sensor Description 68 5.13.2 Drive Cycle Information 68 5.13.3 Intake Air Temperature Sensor Description 69 5.13.4 Drive Cycle Information 70 5.14 Knock Sensor 71 5.14.1 Description 71 5.14.2 Drive Cycle Information 71 5.15 Fuel Tank Level Sensor 73 5.15.1 Description 73 5.15.2 Drive Cycle Information 73 5.16 Throttle Position Sensor 74 5.16.1 Description 74 5.16.2 Drive Cycle Information 75 5.17 Engine Control Module Self Test 76 5.17.1 Description 76 5.17.2 Drive Cycle Information 76 5.18 Ambient Air Temperature Interface 77 5.18.1 Description 77 5.18.2 Drive Cycle Information 77 5.19 Vehicle Speed Interface 78 5.19.1 Description 78 5.19.2 Drive Cycle Information 78 5.20 Transfer Box Control Module Interface 79 5.20.1 Description 79 5.20.2 Drive Cycle Information 79 5.21 CAN System 80 5.21.1 Description 80 5.21.2 Drive Cycle Information 80 Land Rover Revision Date: September 2004 Page 3 of 84

5.22 Fuel Injectors 81 5.22.1 Description 81 5.22.2 Drive Cycle information 81 5.23 Idle Speed Control Actuator 83 5.23.1 Description 83 5.23.2 Drive Cycle Information 83 5.24 Electronic Throttle Interface 84 5.24.1 Description 84 5.24.2 Drive Cycle Information 84 Land Rover Revision Date: September 2004 Page 4 of 84

2 Introduction The Range Rover Petrol Engine Management System consists of the Bosch ME7.2 Engine Control Module (ECM) controlling the BMW 4.4L V8 M62 engine. ME7.2 is a development of the Bosch M5.2.1 Engine Management System used on the Land Rover Thor V8 engine, the major difference being that ME7.2 is a drive-by-wire Engine Management system, i.e. ME7.2 has electronic throttle control. Another significant system difference is the extensive use of a Controller Area Network (CAN) system to provide the interface to other vehicle systems. 2.1 Inputs and Outputs Input Signals Monitored by OBD II? Transmission Control Module (torque reduction request) Yes - Bus check Engine Coolant Temperature Yes Intake Air Temperature Yes Mass Airflow Yes Oxygen Sensors Yes Crankshaft Position/Speed Yes Camshaft Position Yes Throttle Position Yes Vehicle Speed Yes Knock Sensor Yes Driver Demand Sensor No Ambient Air Temperature (via CAN) Yes (no MIL) Soak Time (via CAN) No Fuel Level (via CAN) Yes (no MIL) Radiator Outlet Temperature Yes Cruise Control Switches No Land Rover Revision Date: September 2004 Page 5 of 84

Brake Pedal Position No Transfer Gear Range (via CAN) Yes (no MIL) EVAP System (Leak Diagnosis Module Pump Motor Current) Yes Output Signals Monitored by OBD II? Transmission Control Module Yes Signals checked separately Throttle Actuator Yes Ignition Coils Via Misfire Monitoring Injection Valves Yes Secondary Air Injection Pump and Valve Yes EVAP Canister Purge Valve Yes Switching Valves (Variable Camshaft Timing) Yes Malfunction Indicator Lamp (MIL) (via CAN) Not directly EVAP System (Leak Diagnosis Module Pump Motor and Solenoid Valve) EVAP System (Leak Diagnosis Module Heater) Yes (no MIL) Oxygen Sensor Heating Yes Fuel Pump Relay No Air Conditioning Compressor Relay No Auxiliary Engine Cooling Fan No Thermostat Heating Element No Engine Starter Relay No Yes Land Rover Revision Date: September 2004 Page 6 of 84

3 Mode $06 Data 1. This information needs to be used in conjunction with the monitor descriptions and data setting information. This gives the background on entry conditions and test limits. 2. Not all scan tools work the same way when outputting Mode 6 test data. Some report the raw values, some just report pass or fail. 3. Bit 7 of the Component ID identifies if a passing value must exceed the threshold and many scan tools take this into account when reporting mode 6 information. For example, the Bank 1 Sensor 1 response rate minimum check maybe reported with a component ID of 1, but the scan tool will in this instance show or interpret a test value that is below the threshold as failing and a value that exceeds the threshold as passing. Catalyst Monitoring Test ID Comp. ID 01 Monitored Component From ECM Test Value Conversion Factor From ECM Threshold Conversion Factor 05 Bank 1 Catalyst 0 to 255 x 0.003906 0 to 255 x 0.003906 06 Bank 2 Catalyst 0 to 255 x 0.003906 0 to 255 x 0.003906 Comments Mean corrected value of the downstream sensor signal Upstream Oxygen Sensors Test ID Comp. ID Monitored Component From ECM Test Value Conversion Factor Units From ECM Threshold Conversion Factor Units Comments 02 7 Bank 1 Sensor 1 8 Bank 2 Sensor 1 19 Bank 1 Sensor 1 130 Bank 2 Sensor 1 11 Bank 1 Sensor 1 12 Bank 2 Sensor 1 137 Bank 1 Sensor 1 138 Bank 2 Sensor 1 0 to 65535 x 0.01 seconds 0 to 65535 x 0.01 Divide by 25600, then subtract 1.28 Divide by 25600, then subtract 1.28 seconds Response rate maximum check Response rate minimum check Correction time maximum check Correction time minimum check Land Rover Revision Date: September 2004 Page 7 of 84

Downstream Oxygen Sensors Test ID Comp. ID Monitored Component From ECM Test Value Conversion Factor Units From ECM Threshold Conversion Factor Units Comments 02 7 Bank 1 Sensor 1 8 Bank 2 Sensor 1 19 Bank 1 Sensor 1 130 Bank 2 Sensor 1 11 Bank 1 Sensor 1 12 Bank 2 Sensor 1 137 Bank 1 Sensor 1 138 Bank 2 Sensor 1 0 to 65535 x 0.01 seconds 0 to 65535 x 0.01 Divide by 25600, then subtract 1.28 Divide by 25600, then subtract 1.28 seconds Response rate maximum check Response rate minimum check Correction time maximum check Correction time minimum check Evaporative Emission Control System Canister Purge Valve Test ID Comp. ID 05 Monitored Component From ECM Test Value Conversion Factor Units From ECM Threshold Conversion Factor Units Comments 1 Canister purge 0 to 65535 Subtract none 0 to 65535 Subtract none Purge mixture check valve 32768, then 32768, then result (maximum) 129 divide by 512 divide by 512 Purge mixture check result (minimum) 136 0 to 32767 Divide by 4 rpm 0 to 32767 Divide by 4 rpm Purge Valve idle speed control check (minimum) 136 Divide by 4 Divide by 4 Purge Valve idle speed control check (minimum) Land Rover Revision Date: September 2004 Page 8 of 84

Evaporative Emission Control System Leak Check Test ID Comp. ID 05 Monitored Component From ECM Test Value Conversion Factor Units From ECM Threshold Conversion Factor Units Comments 149 Gross leak 0 to 65535 Divide by ma 0 to 65535 Divide by ma Normal mode for 40 thou 163.84 163.84 leak check 152 Extended mode for 40 thou leak check 19 Reference Pump current too high 146 current check Pump current too low 20 Current change after valve actuation Change over valve check 23 Heater element 0 to 255 Not applicable none 0 to 255 Not applicable none Humidity counter check 150 Fine leak 0 to 65535 Divide by ma 0 to 65535 Divide by ma 20 thou leak check 163.84 163.84 Oxygen Sensor Heaters Test ID Comp. ID 06 Monitored Component 15 Bank 1 Sensor 1 16 Bank 2 Sensor 1 29 Bank 1 Sensor 1 30 Bank 2 Sensor 1 From ECM Test Value Conversion Factor Units From ECM Threshold Conversion Factor Units Comments 0 to 65535 x 2 Ohms 0 to 65535 x 2 Ohms Heater internal resistance Land Rover Revision Date: September 2004 Page 9 of 84

4 OBD Drive Cycle Information The following drive cycles may be used to exercise the monitors described in this document. Drive Cycle A 1 Switch on the ignition for 30 seconds. 2 Ensure engine coolant temperature is less than 60 C. 3 Start the engine and allow to idle for 2 minutes. 4 Connect a generic scan tool and check for fault codes. Drive Cycle B 1 Switch ignition on for 30 seconds. 2 Ensure engine coolant temperature is less than 60 C. 3 Start the engine and allow to idle for 2 minutes. 4 Perform 2 light accelerations, i.e. 0 to 35 mph with light pedal pressure. 5 Perform 2 medium accelerations, i.e. 0 to 45 mph with moderate pedal pressure. 6 Perform 2 hard accelerations, i.e. 0 to 55 mph with heavy pedal pressure. 7 Allow engine to idle for 2 minutes. 8 Connect a generic scan tool and, with the engine still running, check for fault codes. 1 Switch ignition on for 30 seconds. 2 Ensure engine coolant temperature is less than 60 C. 3 Start the engine and allow to idle for 2 minutes. 4 Perform 2 light accelerations, i.e. 0 to 35 mph with light pedal pressure. 5 Perform 2 medium accelerations, i.e. 0 to 45 mph with moderate pedal pressure. 6 Perform 2 hard accelerations, i.e. 0 to 55 mph with heavy pedal pressure. 7 Cruise at 60 mph for 8 minutes. 8 Cruise at 50 mph for 3 minutes. 9 Allow engine to idle for 3 minutes. 10 Connect a generic scan tool and, with the engine still running, check for fault codes. Drive Cycle D 1 Switch ignition on for 30 seconds. 2 Ensure engine coolant temperature is less than 35 C. 3 Start the engine and allow to idle for 2 minutes. Land Rover Revision Date: September 2004 Page 10 of 84

4 Perform 2 light accelerations, i.e. 0 to 35 mph with light pedal pressure. 5 Perform 2 medium accelerations, i.e. 0 to 45 mph with moderate pedal pressure. 6 Perform 2 hard accelerations, i.e. 0 to 55 mph with heavy pedal pressure. 7 Cruise at 60 mph for 5 minutes. 8 Cruise at 50 mph for 5 minutes. 9 Cruise at 35 mph for 5 minutes. 10 Allow engine to idle for 2 minutes. 11 Connect a generic scan tool and check for diagnostic trouble codes. Drive Cycle E 1 Ensure fuel tank is at least a quarter full. 2 Carry out drive cycle A. 3 Switch off ignition. 4 Leave vehicle undisturbed for 20 minutes. 5 Switch on ignition. 6 Connect a generic scan tool and check for diagnostic trouble codes. Drive Cycle F 1 Switch ignition on for 30 seconds. 2 Ensure Engine Coolant Temperature is less than 60 o C (140 o F). 3 Start Engine. 4 Ensure vehicle is in High Range. 5 Allow engine to idle for 2 minutes. 6 Cruise at 50 mph for 2 minutes. 7 Allow engine to idle for 2 minutes. 8 Select Low Range. 9 Allow engine to idle for 2 minutes. 10 Perform 2 light accelerations (0 to 10 mph with light pedal pressure). 11 Perform 2 medium accelerations (0 to 20 mph with moderate pedal pressure). 12 Cruise at 30 mph for 2 minutes. 13 Select High Range. 14 Cruise at 50 mph for 2 minutes. 15 Allow engine to idle for 2 minutes. 16 Connect a generic scan tool and check for diagnostic trouble codes. Land Rover Revision Date: September 2004 Page 11 of 84

5 On Board Monitoring 5.1 Catalyst Monitoring 5.1.1 Description Catalyst monitoring is based on the monitoring of oxygen storage capability. The (non-linear) correlation between conversion efficiency and storage capability has been shown in various investigations. The engine closed loop feedback control results in regular lambda (normalised air/fuel ratio) oscillations in the exhaust gas. These oscillations are damped by the oxygen storage activity of the catalyst. The amplitude of the remaining lambda oscillations downstream of the catalyst indicates the storage capability. The monitoring function compares the signal amplitudes obtained from the downstream oxygen sensors with modelled signal amplitudes. The modelled signal amplitudes are derived from a model of a borderline catalyst. If the measured amplitudes exceed those of the model, then the catalyst is considered to be defective. Unlike the previous catalyst monitoring function, this operates over a single range of engine speed and load. The monitoring function can be broken down into the following sub-sections: - Computation of the downstream oxygen sensor signal amplitudes Modelling of a borderline catalyst and the downstream oxygen sensor signal amplitudes Signal evaluation Fault processing Function enable criteria Land Rover Revision Date: September 2004 Page 12 of 84

5.1.2 Monitoring Structure Start no Catalyst temperature (model) > limit? Calculate catalyst model & amplitudes of modelled O2S & downstream O2S yes no Oxygen sensors OK? Accumulate monitoring time yes yes no EVAP Canister purge factor < limit? yes yes Accumulated time > limit? Downstream amplitude > Modelled amplitude? no no No misfire present? yes Normal A/F control enabled? Catalyst OK no yes Catalyst deteriorated no yes Speed & load within monitoring range? Fault processing yes no High range engaged? no End MIL Land Rover Revision Date: September 2004 Page 13 of 84

Monitoring Cycle Computation of the Downstream Oxygen Sensor Signal Amplitudes The first step is the calculation of the amplitude of the signal oscillations of the oxygen sensor downstream of the catalyst. This is accomplished by extracting the oscillating signal component, computing the absolute value and averaging over time. Modelling of a Borderline Catalyst and the Downstream Oxygen Sensor Signal Amplitudes The model simulates the oxygen storage capability of a borderline catalyst. The signal of the downstream oxygen sensor is simulated in the catalyst model; this is based on real-time engine operating data (air fuel ratio and airflow rate). The amplitude of the modelled signal oscillations is then calculated. Signal Evaluation The signal amplitude of the downstream sensors is compared with the model over a given time. If these signal amplitudes exceed the modelled amplitudes, then the oxygen storage capability of the catalyst is less than that of a borderline catalyst. Fault Processing If the test result for the catalyst in the vehicle shows a lower oxygen storage capability than the model, then a fault is detected and an internal flag will be set. If the fault is detected again during the next drive cycle, then the MIL will be illuminated and a diagnostic trouble code (DTC) stored. Since the monitored engine has a catalyst for each of two cylinder banks, two evaluations are made with differing fault thresholds, one test is for deterioration in one of the catalysts and the second is at a reduced threshold to check for deterioration in both catalysts. Function Enable Criteria The monitoring principle is based on the detection of relevant oscillations of the downstream oxygen sensor signal during regular lambda control. It is necessary to check the driving conditions to ensure that regular lambda control is possible, e.g. fuel cut-off not present. During these conditions and for a certain time afterwards, the computation of the amplitude values and their post-processing is suspended, so that a distortion of the monitoring information is avoided. Land Rover Revision Date: September 2004 Page 14 of 84

5.1.3 Block Diagram of System Operation Rear Oxygen Sensor Voltage Catalyst Temperature Model Calculate Signal Amplitude Signal Evaluation Catalyst Deterioration Factor Engine Speed Engine Load Enable Criteria Time Active Mass Airflow Air Fuel Ratio Catalyst & Oxygen Sensor Signal Modelling Amplitude Determination for the Modelled Signal Fault Processing & Management Bank 2 Deterioration Factor MIL Land Rover Revision Date: September 2004 Page 15 of 84

Component/ System Fault Codes Monitoring Strategy Description Malfunction Criteria Catalyst Monitoring Operation Threshold value Secondary Parameter Enable Conditions Time Required MIL Illumination Catalyst P0420/ Oxygen Bank 1 only (P0420) > 0.301 Engine speed 1500 < RPM < 2800 100 sec/ two driving P0430 storage Or >0.211 and Engine load 18< Relative Load % <52 continuous cycles capability Bank 1 result >= Catalyst temperature > 340 C Bank 2 and (model) Comparison (Bank 1 +Bank 2) Fuel system status closed loop of calculated > 0.500 EVAP canister purge vapor < 10 output voltage factor Or Measured Bank 2 only (P0430) > 0.301 Proportion of total fuel due >= 30% output voltage to purge (oscillation) Or >0.211 and Mass airflow at calculated < 5.56.. < 42.22 g/sec from rear Bank 1 result >= O2S load factor < 3.7.. < 5.4 l/sec Bank 2 and oxygen sensor (Bank 1 +Bank 2) Front Oxygen sensor Complete > 0.500 ageing test (P0133/53) 1.75x standard Transfer gears High range If the above table does not include details of the following enabling conditions: - intake air and engine coolant temperature, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor. 5.1.4 Drive Cycle Information P0420 P0430 Land Rover Revision Date: September 2004 Page 16 of 84

5.2 Misfire Monitoring 5.2.1 Description The method of engine misfire detection is based on evaluating the engine speed fluctuations. In order to detect misfiring at any cylinder the torque of each cylinder is evaluated by metering the time between two ignition events, which is a measure for the mean value of the speed of this angular segment. This means, a change of the engine torque results in a change of the engine speed. Additionally the influence of the load torque will be determined. This means the influences of different road surfaces, e.g. pavement, pot holes etc. If the mean engine speed is to be measured, influences caused by road surfaces have to be eliminated. This method consists of the following main parts: data acquisition, adaptation of sensor wheel is included calculation of engine roughness comparison with a threshold depending on operating points some extreme conditions, during which misfire detections should be disabled for a short time fault processing, counting procedure of single misfire events Land Rover Revision Date: September 2004 Page 17 of 84

5.2.2 Monitoring Structure Start Data Aquisition Segment Duration no Fuel shut off during Coasting Condition yes Calculation of Engine Roughness and Threshold Adaptive Segment Duration Correction Comparison of Threshold with Engine Roughness yes no Extreme Engine Operating Condition yes Fault Processing (--> MIL) End Land Rover Revision Date: September 2004 Page 18 of 84

Monitoring Cycle Data acquisition The duration of the crankshaft segments is measured continuously for every combustion cycle. Sensor wheel adaptation Within a defined engine speed range and during fuel cut-off, the adaptation of the sensor wheel tolerances, instead of misfire detection, is carried out. With progressing adaptation the sensitivity of the misfire detection is increasing. The adaptation values are stored in a non-volatile memory and are taken into consideration for the calculation of the engine roughness. Misfire detection The following operating steps are performed for each measured segment corrected by the sensor wheel adaptation. Calculation of the engine roughness The engine roughness is derived from the differences of the segment durations. Different statistical methods are used to distinguish between normal changes of the segment duration and the changes due to misfiring. Detecting of multiple misfiring If several cylinders are misfiring (e.g. alternating one combustion/one misfire event) the calculated engine roughness values may be so low, that the threshold is not exceeded during misfiring and therefore misfiring would not be detected. Based on this fact, the periodicity of the engine roughness value is used as additional information during multiple misfiring. The engine roughness value is filtered and a new multiple filter value is created. If this filter value increases due to multiple misfiring, the roughness threshold is decreased. By applying this strategy, multiple misfiring is detected reliably. Calculation of the engine roughness threshold value The engine roughness threshold value consists of the base value, which is determined by a load/speed dependent map. During warm-up an engine coolant temperature dependent correction value is added. In case of multiple misfiring the threshold is reduced by an adjustable factor. Without sufficient sensor wheel adaptation the engine roughness threshold is limited to a speed dependent minimum value. A change of the threshold towards a smaller value is limited by a variation constant. Determination of misfiring Misfire detection is performed by comparing the engine roughness threshold value with the engine roughness value. If a misfire event is detected in a cylinder, the misfire detection of the next cylinder in firing order is deactivated to prevent a faulty diagnosis. Statistics, fault processing Within an interval of 1000 crankshaft revolutions the detected misfiring events are added for each cylinder. If the sum of all cylinder misfire incidents exceeds a predetermined value, the fault code for emission relevant misfiring is preliminarily stored. If only one cylinder is misfiring, a cylinder selective fault code is stored. If more than one cylinder is misfiring, the fault code for multiple misfiring is also stored. Within an interval of 200 crankshaft revolutions the detected number of misfiring events is weighted and calculated for each cylinder. The weighting factor is determined by a load/speed dependent map. If the sum of cylinder misfire incidents exceeds a predetermined value, the fault code for indicating catalyst damage relevant misfiring is stored and the MIL is illuminated at once (blinking). Land Rover Revision Date: September 2004 Page 19 of 84

If the cylinder selective count exceeds the predetermined threshold, the following measures take place: the oxygen sensor closed loop system is switched to open loop the cylinder selective fault code is stored. If more than one cylinder is misfiring, the fault code for multiple misfire is also stored the fuel supply to the respective cylinder is cut-off All misfire counters are reset after each interval. Land Rover Revision Date: September 2004 Page 20 of 84

5.2.3 Fault Processing for Emissions Relevant Misfire Start Interval Counters A + 1 and B + 1 yes Interval Counter A > 1000 no no Interval Counter B > 200 yes Interval Counter A = 0 Cylinder Fault Counters A = 0 Interval Counter A = 0 Cylinder Fault Counters A = 0 yes Misfire event no no Misfire event yes Cylinder Fault Counter Ax + 1 Cylinder Fault Counter Bx + weighted value yes Sum of Faults Counters Ai exceeds emission relevant misfiring frequency no no Sum of Faults Counters Bi exceeds misfire frequency for Catalyst Damage yes MIL on (2 driving cycles) MIL on at once (blinking) End Land Rover Revision Date: September 2004 Page 21 of 84

Component/ System Misfire Fault Codes Monitoring Strategy Description Malfunction Criteria Misfire Monitoring Operation Threshold value Secondary Parameter Enable Conditions Time Required MIL Illumination P0301/0302 Crankshaft FTP emissions Engine speed 480 < RPM < 6100 1000 two driving P0303/0304 speed threshold number Engine load change < 32 % / revolutions revolutions/ cycles P0305/0306 fluctuation of excedance >> > 2.0 %/ 1000 Engine speed change <5300 RPM/sec continuous P0307/0308 once within the first revolutions Rough road (wheel) < 17-24 m/sec 2 P0316 Multiple 1000 revolutions ASC Not active misfire after engine start Transfer gears High range P0301/0302 >> four times after > 2.0 %/ 1000 P0303/0304 the first 1000 revolutions P0305/0306 revolutions P0307/0308 have elapsed P0316 Multiple misfire P0301/0302 catalyst damage Mapped against engine load 200 immediately P0303/0304 23.0-12.5 % at 1000 rpm revolutions/ P0305/0306 16.2-9.0 % at 2000 rpm continuous P0307/0308 13.6-6.1 % at 3000 rpm 12.0-6.1 % at 4000 rpm P1315 Multiple 9.8-6.2 % at 5000 rpm misfire 8.6-8.0 %at 6000 rpm If the above table does not include details of the following enabling conditions: - intake air and engine coolant temperature, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor. 5.2.4 Drive Cycle Information P0316 P0301 P0302 P0303 P0304 P0306 P0307 P0308 P1315 Land Rover Revision Date: September 2004 Page 22 of 84

5.3 Secondary Air Injection System Monitoring 5.3.1 Description At cold start the secondary air injection pump and valve are switched on for their normal operating function. The secondary air delivered into the exhaust gas causes a lean mixture indicated by the output voltage of the front oxygen sensor. Any time the oxygen sensor indicates a rich mixture (voltage > a fixed limit) within a predetermined time range and the calculation of the relative secondary air mass is < a defined threshold, the secondary air injection system appears to be faulty. A correction procedure follows immediately after the secondary air injection system is switched off. The air fuel ratio influence is determined by the deviation of the lambda-controller. If influence < a fixed threshold, finally a fault will be detected. If influence > a fixed threshold the results of the diagnosis will be rejected As long as a lean mixture (voltage < a fixed limit) is indicated from the front oxygen sensor within a predetermined time range and the correction of air fuel ratio influence (after secondary air injection pump shuts-off) is < a fixed threshold a fault will also be detected. Land Rover Revision Date: September 2004 Page 23 of 84

5.3.2 Monitoring Structure Start of monitoring procedure No No Required conditions fulfilled yes Oxygen sensor lean indication No Calculation of relative secondary air injection mass Accumulated time lean indication > limit No <= threshold Yes Shut off secondary air injection pump Intermediate part fault processing Calculation/Correction of air fuel ratio influences <= limit Yes Main part fault processing MIL End of monitoring Land Rover Revision Date: September 2004 Page 24 of 84

Component/ System Fault Codes Monitoring Strategy Description Secondary Air Injection System Monitoring Operation Malfunction Criteria Threshold value Secondary Parameter Enable Conditions Time Required MIL Illumination Secondary P0414/1413 circuit continuity Voltage range B+ < 3 V Battery voltage 9.5 V < B+ < 17 V immediately/ two driving Air short to GND (minimum) Engine speed > 40 RPM continuous cycles Injection P0412/0418 Circuit continuity Voltage range B+ < 5 V System open circuit (minimum) P0413/1414 Circuit continuity Current range I > 2.4 A short to B+ (maximum) P0491/0492 Functional check O2S signal < 0.4 Mass Airflow 3.33 < m g/sec < 42.22 20...60 sec/ (low flow limit) (rich indication) (including Air ECT 3 < ECT C < 75 once per fuel ratio IAT 3 < IAT C < 50 driving cycle influence) Calculated air density > 0.68 O2S status Heated up Relative air mass integral > 0.475 A/F influence < 3600 g (secondary air mass) Battery voltage > 10.8 V Transfer gears High range If the above table does not include details of the following enabling conditions: - intake air and engine coolant temperature, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor. 5.3.3 Drive Cycle Information P0414 P1413 P0412 P0418 P0413 P1414 P0491 P0492 Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable Land Rover Revision Date: September 2004 Page 25 of 84

5.4 Evaporative Emission System Leak Measurement 5.4.1 Description of Leak Measurement The evaporative emission system monitoring permits the detection of leaks in the evaporative emission system with a diameter of 0.020" and or greater. By means of a Diagnostic Module Tank Leakage (DM-TL), an electrical actuated pump located at the atmospheric connection of the evaporative emission canister, a pressure test of the evaporative emission system is performed in the following order: During the Reference Leak Measurement, the electrical actuated pump delivers through the reference restriction. The ECM system measures the pump s electrical current consumption in this section. throttlebody EVAP canister purge valve engine reference leak EVAP canister solenoid tank M pump filter ambient air Land Rover Revision Date: September 2004 Page 26 of 84

During the Leak Measurement, the electrical actuated pump delivers through the EVAP canister into the fuel tank system. The pressure in the evaporative emission system may be up to 2500 Pa depending on the fuel level in the tank. The ECM measures the pump s electrical current consumption. A comparison of the currents of the reference leak measurement and the leak measurement is a measure for the leakage in the tank. throttlebody EVAP canister purge valve engine EVAP canister solenoid tank reference leak ambient air pump filter Land Rover Revision Date: September 2004 Page 27 of 84

After the test, the remaining pressure in the evaporative system is bled off through the EVAP canister by switching off the pump and solenoid. EVAP canister purge valve EVAP canister Land Rover Revision Date: September 2004 Page 28 of 84

5.4.2 Monitoring Structure end No engine shut-down release conditions met for leak detection Yes reference leak measurement conditions - voltage supply in range - engine control module (ECM) running-on - no RPM detected - ambient air temperature in range - elevation < threshold - EVAP canister load in range - fuel level in range - EVAP canister purge valve closed - no component errors (DMTL, solenoid valve, EVAP canister purge valve) detected - start driving cycle detected - transfer gears in high range reference current > upper threshold for reference measurement Yes component error detected No reference current < lower threshold for reference measurement Yes component error detected No humidity detected Yes end No rough leak measurement filler cap removal - refueling Yes end No humidity detected Yes end No min. pump current (while rough leak measurement) >= reference current + delta pump current Yes component error detected No No current (end of rough leak measurement) < 1. threshold Yes Land Rover Revision Date: September 2004 Page 29 of 84

Yes enhanced rough leak measurement No current (end of enhanced rough leak measurement) < 2. threshold Yes reference leak measurement No reference current > upper threshold for reference measurement Yes component error detected No reference current < lower threshold for reference measurement Yes component error detected No humidity detected Yes end No current (end of enhanced rough leak measurement) < 2. threshold Yes Rough Leak detected No Refueling detected or rough leak counter >= threshold Yes No No Rough Leak detected Diagnosis Frequency and MIL illumination Land Rover Revision Date: September 2004 Page 30 of 84

Yes small leak measurement filler cap removal - refueling Yes end No humidity detected Yes end No No current (end of small leak measurement) < reference current Yes reference leak measurement reference current > upper threshold for reference measurement Yes component error detected No reference current < lower threshold for reference measurement Yes component error detected No humidity detected Yes end No current (end of small leak measurement) < reference current Yes small leak detected No leak proof detected Land Rover Revision Date: September 2004 Page 31 of 84

Diagnosis Frequency and MIL illumination: No refueling detected; leak > 0.040" Soak > 5h Driving Cycle Soak > 5h Driving Cycle Soak > 5h Driving Cycle Soak > 5h Driving Cycle Ignition ON OFF Leak diagnosis Cycle Bit If Leak detected: Failure Bit MIL ON OFF < 2 min after engine start (tank fuel level settled) Land Rover Revision Date: September 2004 Page 32 of 84

Diagnosis Frequency and MIL illumination: After refueling detected; leak > 0.020" Soak > 5h Driving Cycle Soak > 5h Driving Cycle Soak > 5h Driving Cycle Soak > 5h Driving Cycle Ignition ON OFF Refueling detected Leak diagnosis Cycle Bit If Leak detected: Failure Bit MIL ON OFF after engine start Land Rover Revision Date: September 2004 Page 33 of 84

5.4.3 Description of Evaporative Emission Canister Purge System Flow Check The purge flow from the EVAP canister through the EVAP canister purge valve is monitored after fuel system adaptation is completed and the lambda controller is at closed loop condition. The diagnosis is started during regular purging. 5.4.4 Monitoring Structure Step 1 start of monitoring procedure 1. Fuel system adaptation has finished 2. Closed loop condition of the lambda controller Open EVAP canister purge valve (regular purging) O2S controller shift (rich or lean) > threshold? yes no Step 2 1. Regular purging finished 2. Engine at idle 3. Closed loop condition of the O2S controller Open and close EVAP canister purge valve abruptly (several times) end of monitoring procedure yes engine speed variation > threshold? no Store EVAP system fault MIL Fault processing Land Rover Revision Date: September 2004 Page 34 of 84

Monitoring Cycle of Evaporative Emission Canister Purge System Flow Check Step 1 - For rich or lean mixture Flow through the EVAP canister purge valve is assumed as soon as the lambda controller is compensating for a rich or a lean shift. After this procedure the diagnosis is completed and the EVAP canister purge system resumes working normally. Step 2 - For a stoichiometric mixture In this case the lambda controller does not need to compensate for a deviation. Therefore, after finishing the regular purging, the EVAP canister purge valve is opened and closed abruptly several times. The effect of additional cylinder charge will trigger a variation of the engine idle speed. A predetermined value is reached if the system functions properly and the diagnosis procedure is completed. To start the diagnosis function (step 2) several conditions have to be satisfied. vehicle speed = 0 engine at idle speed closed loop of lambda controller engine coolant temperature > fixed limit transfer gears in high range Furthermore if the diagnosis has already been started and one of the conditions has not been satisfied continuously, the process will be interrupted and started again later. engine idle speed variation < fixed limit Land Rover Revision Date: September 2004 Page 35 of 84

Fuel Evaporative Emission System Monitoring Component/ System Fault Codes Monitoring Strategy Description Malfunction Criteria Threshold Value Secondary Parameter Enable Conditions Time Required MIL Illumination Evaporative P0441 Flow check purge vapor factor -2.7< purge vapor Fuel system Entry conditions 40 sec/ two driving Emission (rich or lean -4 >> fresh air; factor <3.8 adaptation satisfied once per cycles Canister mixture) 0 >> lambda 1; ECT > 65 C driving cycle Purge 32 >> saturated Fuel system status Closed loop System fuel vapor Target idle speed <= 750 RPM Normal purge on Flow check engine speed -2500 < INDTE < Vehicle speed 0 mph (stoichiometric variation 400 RPM Engine speed Idle RPM mixture) (accumulated (> 3 of maximum ECT > 80 C engine speed 5 samples) Commanded idle < ± 30 RPM difference per speed variation time unit =INDTE) Altitude condition >= 0.719 Transfer gears High range Evaporative P0445 Circuit continuity - voltage range B+ < 3 V Battery voltage 9.5V < B+ < 17V immediately/ two driving Emission short circuit to GND (minimum) Engine speed > 40 RPM continuous cycles Canister P0443 Circuit continuity - voltage range B+ < 5 V Purge Valve open circuit (minimum) P0444 Circuit continuity - current range I > 2.4 A short circuit to B+ (maximum) EVAP P2401/0447 Circuit continuity - voltage range B+ < 3 V Battery voltage 9.5V<B+< 17V immediately/ two driving System short circuit to GND (minimum) Engine speed > 40 RPM continuous cycles Leak P2400/2450 Circuit continuity - voltage range B+ < 5 V Diagnosis open circuit (minimum) Module P2402/0448 Circuit continuity - current range I > 2.4 A DMTL short circuit to B+ (maximum) Land Rover Revision Date: September 2004 Page 36 of 84

Fuel Evaporative Emission System Monitoring Component/ System Fault Codes Monitoring Strategy Description Malfunction Criteria Threshold Value Secondary Parameter Enable Conditions Time Required MIL Illumination EVAP P0455 Current rough leak system leak Pump current < ECT at start > 2 C < 300 sec four driving System end greater ( 0.040") threshold AAT 2 C AAT37 C cycles Leak than threshold 0.16 K1 0.28 Altitude condition 0.72 Diagnosis 0.60 K2 0.80 Soak time > 18000 sec Module Last driving cycle > 1200 sec DMTL 1. Threshold = Time after engine 3 sec pump idle current shut off + K1*(reference Fuel tank level 15% < Fuel tank current idle level < 85% current) ECM running on True Battery voltage 10.95< B+<14.5V 2. Threshold = EVAP canister load < 3 reference current Refueling during + 1.2 ma K2*(reference diagnostic current idle Filler cap removal - 1.0 ma current) during diagnostic Humidity 0.5 ma during measurement Transfer gears High range EVAP P0442 Current small leak System leak Threshold = ECT at start > 2 C < 450 sec four driving System end greater or (0.020") reference leak AAT 2 C AT37 C cycles Leak equal threshold current Altitude condition 0.72 Diagnosis Soak time > 18000 sec Module Last driving cycle > 1200 sec DMTL Time after engine 3 sec shut off Fuel tank level 15% < Fuel tank level < 85 % ECM running on True Land Rover Revision Date: September 2004 Page 37 of 84

Fuel Evaporative Emission System Monitoring Component/ System Fault Codes Monitoring Strategy Description Malfunction Criteria Threshold Value Secondary Parameter Enable Conditions Time Required MIL Illumination Battery voltage 10.95< B+ <14.5V EVAP canister load < 3 Refueling Detected Rough leak diagnosis 14 counter Refueling during + 1.2 ma diagnostic Filler cap removal - 1.0 ma during diagnostic Humidity 0.5 ma during measurement Transfer gears High range P2405 Current during Current range Pump current ECT at start > 2 C 10 sec four driving reference leak (minimum) < 15mA AAT 2 C AAT37 C cycles P2406 measurement Current range Pump current Altitude condition 0.72 (maximum) > 40mA Soak time > 18000 sec Last driving cycle > 1200 sec EVAP P2404 Current change Current decrease Reference current Time after engine 3 sec 15 sec four driving System after actuating - pump idle shut off cycles Leak valve current > 2mA Fuel tank level 15% < Fuel tank < 450 sec Diagnosis P2407 Signal / heater Humidity counter counter > 5 level < 85% Module element overflow ECM running on True DMTL Battery voltage 10.95< B+< 14.5V Canister load < 3 Humidity 0.5 ma during measurement If the above table does not include details of the following enabling conditions: - intake air and engine coolant temperature, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor. Land Rover Revision Date: September 2004 Page 38 of 84

5.4.5 Drive Cycle Information P0441 P0445 P0443 P0444 P2401 Drive Cycle A P0447 Drive Cycle A P2400 Drive Cycle A P2450 Drive Cycle A P2402 Drive Cycle A P0448 Drive Cycle A P2405 Not Applicable P2406 Not Applicable P2404 Not Applicable P2407 Not Applicable P0442 Not Applicable P0455??? Land Rover Revision Date: September 2004 Page 39 of 84

5.5 Fuel System Monitoring 5.5.1 Description Mixture Primary Control The air mass taken in by the engine and the engine speed are measured. These signals are used to calculate an injection signal. This mixture primary control follows fast load and speed changes. Lambda-Control The ECM compares the oxygen sensor signal of the sensor upstream of the catalyst with a reference value and calculates a correction factor for the primary control. Adaptive Primary Control Drifts and faults in sensors and actuators of the fuel delivery system as well as un-metered air leakage into the intake system influence the primary control. This causes deviations in the air fuel ratio. The adaptive primary control determines the controller correction in two different ranges. Ranges of Learning Correction Coefficients tra and fra Relative Load (RL) RLU2 QU2 QL2 Range 2 (fra) QU1 Range 1 (tra) NU1 RLL2 Engine speed Land Rover Revision Date: September 2004 Page 40 of 84

Range 1 Determination of additive correction per time unit Range 2 Determination of multiplicative correction Lambda deviations in range 1 are compensated by an additive correction value multiplied by an engine speed term. By this means an additive correction per time unit is derived. Lambda deviations in range 2 are compensated by a multiplicative factor. Each value is determined only within its corresponding range. But each adaptive value corrects the primary control within the whole load and speed range of the engine. After the next start, the stored adaptive values are included in the calculation of the primary control; just before the closed loop fuelling control is activated. Abbreviations for the fuel delivery system NU1 Upper engine speed threshold, range 1 QU1 Upper air flow threshold, range 1 tra Additive learning correction coefficient per time unit (range 1) TRADN Lower diagnosis threshold of tra TRADX Upper diagnosis threshold of tra QL2 Lower air flow threshold, range 2 QU2 Upper air flow threshold, range 2 RLU2 Upper engine load threshold, range 2 RLL2 Lower engine load threshold, range2 fra Multiplicative learning correction coefficient (range 2) FRADN Lower diagnosis threshold of fra FRADX Upper diagnosis threshold of fra Diagnosis of fuel delivery system Faults in the fuel delivery system can occur which cannot be compensated for by the adaptive control. In this case the adaptive values leave a predetermined range. If the adaptive value is outside this predetermined range, and if the condition is again present on a subsequent drive cycle, the MIL is illuminated and the appropriate DTC's are stored. Land Rover Revision Date: September 2004 Page 41 of 84

5.5.2 Monitoring Structure reference value primary control mass air flow speed sensor signal A/F controller Range 2 OBD fault handling MIL Range 1 speed correction Engine exhaust oxygen sensor Land Rover Revision Date: September 2004 Page 42 of 84

Start Fuel Control and Adaptation no Adaptation Coefficients fra & tra almost un-changed yes Wait until fra active for more than a certain time Wait until tra active for more than a certain time Set Cycle Flag yes TRADN < tra < TRADX no Fault Processing yes FRADN < fra < FRADX no End MIL Land Rover Revision Date: September 2004 Page 43 of 84

Component/ System Fault Codes Monitoring Strategy Description Malfunction Criteria Fuel System Monitoring Threshold value Secondary Parameter Enable Conditions Time Required MIL Illumination Fuel Fuel trim Fuel system status CL and not full load two driving System limits ECT >= 67.5 C cycles exceeded Intake air temperature < 60.0 C EVAP canister purge Not active system Throttle angle From <= 58.6% @ 400 RPM to <= 93.75% @ 6000 RPM Transfer gears High range P2177/2178 Bank 1 fra value <-11% or Relative engine load 15.8% < RL < 99% Up to lean/rich (multiplicative >20% Engine air flow 15.28 g/sec < Air Flow < 30 sec/ P2179/2180 Bank 2 correction) 275.0 g/sec continuous lean/rich outside limit P2187/2188 Bank 1 tra value (additive <-5.02% or Engine speed < 1000 rpm Up to lean/rich correction/engine > 3.98% Engine air flow < 8.33 g/sec 20 sec/ P2189/2190 Bank 2 rev)outside limit fra check Complete continuous lean/rich If the above table does not include details of the following enabling conditions: - intake air and engine coolant temperature, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor. 5.5.3 Drive Cycle Information P2177 P2178 P2179 P2180 P2187 P2188 P2189 P2190 Land Rover Revision Date: September 2004 Page 44 of 84

5.6 Oxygen Sensor Monitoring 5.6.1 Description The response rates of the up stream oxygen sensors are monitored by measuring the period of the lambda control oscillations. + - Engine Catalyst A/F Controller upstream oxygen sensor Period Monitoring detection of slow O2S's Land Rover Revision Date: September 2004 Page 45 of 84

5.6.2 Monitoring Structure Begin End of diagnosis engine run within engine speed, load and ehaust temperature range YES period measurement YES period averaging delay counter > Limit count number of measured periods NO wait for next period count number > limit YES engine run within engine speed, load and exhaust temperature range NO period > maximum YES fault: period higher than threshold NO NO NO oxygen sensor o.k. fault processing end of diagnosis Land Rover Revision Date: September 2004 Page 46 of 84 MIL

Diagnosis Procedure of the Monitor Sensor (Downstream) The activity of the monitor sensor after reaching operating conditions is determined by two different procedures. A ) Oscillation Check (Line Crossing) If the following checks are correct, the monitor sensor will be regarded as Satisfactory: The monitor sensor signal (sensor voltage) is than the nominal value of the TV-Correction and voltage increases, if the λ control goes to the lean side, or The monitor sensor signal (sensor voltage) is < than the nominal value of the TV-Correction and voltage decreases, if the λ control goes to the rich side. B ) Fuel Cut Off Check Additionally to the above-mentioned checks the signal behavior of the monitor sensor is checked in case of fuel cut off. Therefore the monitor sensor voltage has to be below a given nominal value in case of fuel cut off. If the monitor sensor is detected faulty by check A or B, a DTC is stored and the MIL is illuminated at the next driving cycle. Land Rover Revision Date: September 2004 Page 47 of 84

5.6.3 Oxygen Sensor Heater Monitoring Description For proper function of the oxygen sensor, the sensor element must be heated. A non-functioning heater delays the sensor readiness for closed loop control and influences emissions. The monitoring function measures both, sensor heater current (voltage drop over a shunt) and the heater voltage (heater supply voltage) to calculate the sensor heater resistance. The monitoring function is activated once per trip, if the heater has been switched on for a certain time period and the current has stabilized. Characteristics: - ECM controlled switching of the sensor heater. One shunt for each pair of O2 sensors upstream and downstream of the catalysts for current measurement. Land Rover Revision Date: September 2004 Page 48 of 84

5.6.4 Oxygen Sensor Heater Monitoring Structure Engine Start Ru = Upper resistance threshold; RL = Lower resistance threshold Switching on of O2S heating Calculation of sensor heater resistance: Voltage Resistance sensor heater = Voltage heater / sensor heater Resistance heater Delay time for O2S warming up R sensor heater > R R sensor heater no < U R L yes yes Fault: heater resistance upper than upper threshold Fault: heater resistance lower than lower threshold Fault pro- cessing no O2S heater o.k. MIL Land Rover Revision Date: September 2004 Page 49 of 84

Oxygen Sensor Circuit Monitoring Monitoring for electrical faults in the O2 sensors both upstream and downstream of the catalyst. Implausible voltages: Analogue to Digital Converter voltages exceeding the maximum threshold (VMAX) are caused by a short circuit to B+. Analogue to Digital Converter voltages falling below the minimum threshold (VMIN) are caused by a short circuit of the sensor signal or sensor ground to the ECM ground An open circuit of the sensor can be detected if the Analogue to Digital Converter voltage remains within a specified range after the sensor has been heated for a certain time. Component /System Fault Codes Monitoring Strategy Description Malfunction Criteria Oxygen Sensor Monitoring Threshold value Secondary Parameter Enable Conditions Time Required MIL Illumination Oxygen P0133/0153 Response O2S signal > 3.0 sec Idle speed variation 1400 < RPM < 2600 immediately/ two driving Sensor rate Period Engine load variation 20<Relative Load%<54 continuous cycles (front) (average over Catalyst temperature > 350 C 15 periods) (model) EVAP canister purge Off or On for >10s status Transfer gears High range P0134/0154 Circuit continuity Voltage 0.401 V < B+ < 0.499 V 15 sec/ (disconnection) continuous P0132/0152 Range check Maximum > 1.081V 5.2 sec/ (high) voltage continuous P0130/0150 Range check Minimum < 0.04 V Post Catalyst sensor >= 0.499V (low) voltage Or ECT < 39.8 C Time after start > 1.0 sec ECT at power down > 60 C Or 0.060 V <= B+ Post Catalyst sensor >= 0.499V 15 sec/ Or < 0.382 V 0.499 V <= B+ <= 1.081 V Post Catalyst sensor < 0.103V continuous 25 sec/ continuous Land Rover Revision Date: September 2004 Page 50 of 84

Component /System Fault Codes Monitoring Strategy Description Malfunction Criteria Oxygen Sensor Monitoring Threshold value Secondary Parameter Enable Conditions Time Required P2A00/2A03 Correction Controller <-0.5 or > 0.6 sec Engine speed 1200 < RPM < 3000 210 sec/ correction time Relative engine load 18<Relative Load%< 50 continuous Catalyst temperature > 200 C (model) Transfer gears High range P0040 Exchanged Fuel control Bank 1 > 1.20 and Variable camshaft No faults present 5.0 sec/ sensor factor Bank 2 < 0.80 control continuous connectors Or Bank 1 < 0.80 and Bank 2 > 1.20 Heater Engine speed > 25 RPM immediately/ (bank 1 Battery voltage 10.74 V < B+ < 15.54 V continuous /bank 2) Exhaust gas temperature > Dew point Transfer gears High range P0031/0051 Circuit continuity Heater voltage <= 2.34 V Heater Off 0.05 sec./ short circuit to continuous GND P0032/0052 Circuit continuity Heater voltage >= 3.59 V Heater On short circuit to B+ P0030/0050 Circuit continuity Heater voltage 2.34V < B+ < 3.59V Heater Off open circuit P0135/0155 Heater Calculated 11.5 k... 2.1 k Heater on for > 135 sec 12 sec/ resistance resistance (>250... < 400 C) Exhaust gas 250 C <=T <= 600 C continuous (internal) (dependant on temperature exhaust gas model temperature) MIL Illumination Land Rover Revision Date: September 2004 Page 51 of 84