DIAGNOSIS AND TESTING

Transcription

1 Steering System DIAGNOSIS AND TESTING Steering System Special Tool(s) Dial Thermometer F 023-R0007 or equivalent Special Tool(s) Worldwide Diagnostic System (WDS) 418-F224, New Generation STAR (NGS) Tester 418-F052, or equivalent diagnostic tool with appropriate adapter cable Material Item Specification 73III Automotive Meter Mercon Multi-Purpose R0057 or equivalent (ATF) Transmission Fluid XT-2-QDX Principles of Operation Variable Assist Power Steering (VAPS) The VAPS system controls the level of power Power Steering Analyzer assistance available to the driver based on vehicle 211-F001 ( ) or speed. Below 3.2 km/h (2 mph), full power steering equivalent assist is provided to lessen steering efforts and increase maneuverability. Between 3.2 km/h (2 mph) and 191 km/h (119 mph), steering assist will decrease gradually at a calibrated rate to raise steering efforts for increased directional stability and Gauge, Spring Tension greater road feel. Above 191 km/h (119 mph), (T74P-3504-Y) steering assist is constant. The front electronic module (FEM) outputs a pulse-width-modulated (PWM) current to the control valve actuator. The control valve actuator controls the hydraulic valve that determines the amount of hydraulic assist provided to the steering gear. The DIS/EDIS Tach Adapter amount of assistance provided varies with the 418-F102 ( ) or control valve actuator current, which is based on equivalent vehicle speed according to a look-up table internal to the FEM. The FEM pulse-width modulates the control valve actuator current to provide the desired amount of assistance. The amount of hydraulic steering assistance provided by the VAPS subsystem Flex Probe Kit is proportional to the average control valve current. 105-R025B The vehicle speed is provided to the FEM through the standard corporate protocol (SCP) network from the anti-lock brake system (ABS). (Continued) Copyright 2002, Ford Motor Company Last updated: 11/13/2003

2 Steering System The engine rpm is provided to the FEM through the Visual Inspection Chart SCP network from the powertrain control module Mechanical Electrical (PCM). The FEM uses the engine rpm to determine Fluid level Rear battery junction if the engine is running. The FEM will only output Tire pressure box (RBJB) relay 5 control valve actuator current when the engine is Tires Rear battery junction running to minimize noise, vibration, or harshness Drive belt box (RBJB) fuse 11 when the engine is off. The FEM will assume the Drive belt tensioner (30A) engine is running only if the engine rpm is greater Steering column Battery junction box alignment (BJB) fuse 30 (5A) than 100 rpm. Tie rod ends Front electronic module Upon engine start, the FEM will provide a 200 Suspension components (FEM) millisecond full-on pulse followed by a 150 Steering column shaft Wiring millisecond full-off pulse to the control valve U-joints Connectors Intermediate shaft bolts actuator. rmal VAPS system operation will begin Power steering reservoir after this cleaning stroke is complete. In an event baffle that the rpm signal is invalid from the PCM (less Power steering reservoir than 100 rpm), and the vehicle speed is less than filter 1.6 km/h (1 mph), the VAPS system will not carry Power steering pressure lines, fittings or O-rings out the cleaning stroke or apply current to the Power steering return control valve actuator. When the engine speed hoses and clamps exceeds 100 rpm, the system carries out the Steering gear cleaning stroke and begins applying calibrated Power steering pump current to the actuator. Inspection and Verification 3. NOTE: The 3 areas that should be inspected for possible contamination are the power 1. Verify the customer concern. steering reservoir filter, flow control and 2. Visually inspect for obvious signs of pressure relief valve in the pump, and the check mechanical damage. valve in the inlet port on the power steering gear (if equipped). Inspect the power steering fluid for the following conditions: Aerated or foamy: Purge the power steering system. Refer to Power Steering System Purging in this Overheating or contamination: Flush the power steering system. Refer to Power Steering System Filling in this 4. Check the power steering system for fluid leaks. Check the power steering fluid level. NOTE: It may be necessary to add power steering fluid to achieve the correct level. With the ignition OFF: Wipe off the power steering pump, power steering pressure hose, power steering return hose, power steering fluid cooler, hose assembly and steering gear.

3 Steering System CAUTION: Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump can occur. Start the engine and turn the steering wheel from stop-to-stop several times and check for leaks. If a fluid leak from the steering line-to-steering gear clamp plate is evident, refer to Steering Gear in this 5. Inspect the power steering pressure and return hoses, fittings and O-rings for leaks. If a leak is detected at a power steering pressure or return hose, install a new hose. Refer to Power Steering Pump in this If a leak is detected at the power steering reservoir, install a new reservoir. Refer to Power Steering Reservoir in this If a leak is detected at a constant tension spring clamp, verify that the hose is fully installed on the fitting and that the hose clamp is correctly positioned. If the leak remains, install a new screw clamp. If a leak is detected at a screw clamp joint, tighten the screw clamp. If the leak remains, inspect the tube end and install a new hose. Refer to Power Steering Pump in this If a leak is detected at the power steering pump, install a new power steering pump. Refer to Power Steering Pump in this NOTE: To inspect for leaks it may be necessary to If a leak is detected between a fitting nut, remove the squeeze-type clamp from the steering seal the fitting nut using a Teflon joint seal. gear boots. If a leak is detected at a fitting or clamp 6. Inspect the power steering gear for leaks. If a plate, tighten to specification. If leak is still leak is detected at the power steering gear, evident, visually inspect the fittings, clamp plate, O-rings, and Teflon seals. Install new as necessary. Refer to Steering Gear in this install a new power steering gear. Refer to Steering Gear in this

4 Steering System External Leak Check Potential Power Rack-and-Pinion Steering Gear Leak Points 7. If an obvious cause for an observed or reported concern is found, correct the cause before proceeding to the next step.

5 Steering System If the concern remains after the inspection, response/not equipped for FEM, refer to connect the diagnostic tool to the data link Section connector (DLC) located beneath the instrument System passed, retrieve and record the panel, and select the vehicle to be tested from continuous diagnostic trouble codes (DTCs), the diagnostic tool menu. If the diagnostic tool erase the continuous DTCs and carry out the does not communicate with the vehicle: self-test diagnostics for the FEM. Check that the program card is correctly 11. If the DTCs retrieved are related to the concern, installed. go to the Front Electronic Module (FEM) Check the connections to the vehicle. Diagnostic Trouble Code (DTC) Index to Check the ignition switch position. continue diagnostics. 9. If the diagnostic tool still does not communicate 12. If no DTCs related to the concern are retrieved, with the vehicle, refer to the tester manual. proceed to next step to continue diagnostics. 10. Carry out the diagnostic tool data link test. If 13. If an obvious cause for an observed or reported the diagnostic tool responds with: concern is found, correct the cause before proceeding to the next step. SCP or ISO; all electronic control units no response/not equipped, refer to Section 14. If the cause is not visually evident, verify the symptom and GO to Symptom Chart. Front Electronic Module (FEM) Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1342 ECU is Defective FEM CLEAR trhe DTC. RETRIEVE the DTCs. If DTC B1342 is retrieved, INSTALL a new FEM. REFER to Section REPEAT the self-test. C1924 VAPS Solenoid Actuator FEM GO to Pinpoint Test B. Output Short to Ground C1925 VAPS Solenoid Actuator FEM GO to Pinpoint Test C. Return Circuit Failure Steering System Symptom Definitions Drift/Pull Pull is desribed as a tugging sensation, felt by the hands on the steering wheel, that must be overcome to keep the vehicle going straight. Drift describes what a vehicle with this condition does with the hands off the steering wheel. A vehicle-related drift/pull, on a flat road, can cause a consistent deviation from the straight-ahead path and require constant steering input in the opposite direction to counteract the effect. Drift/pull can be induced by conditions external to the vehicle (i.e., wind, road camber). Excessive Steering Wheel Play Excessive steering wheel play is a condition in which there is too much steering wheel movement before the wheels move. A small amount of steering wheel free play is considered normal. Feedback Feedback is a roughness felt in the steering wheel when the vehicle is driven over rough pavement. Hard Steering or Lack of Assist Hard steering or lack of assist is experienced when the steering wheel effort exceeds specifications. Hard steering can remain constant through the full turn or occur near the end of a turn. It is important to know the difference between hard steering/lack of assist and binding.

6 Steering System Hard steering or lack of assist can result from either hydraulic or mechanical conditions. It is extremely important to know if this concern occurs during driving or during high-effort parking maneuvers. Nibble Sometimes confused with shimmy, nibble is a condition resulting from tire interaction with various road surfaces and observed by the driver as small rotational oscillations of the steering wheel. Poor Returnability/Sticky Steering Poor returnability and sticky steering is used to describe the poor return of the steering wheel to center after a turn, or the steering correction, is completed. Shimmy Shimmy, as observed by the driver, is large, consistent, rotational oscillations of the steering wheel resulting from large, side-to-side (lateral) tire/wheel movements. Shimmy is usually experienced near 64 km/h (40 mph), and can begin or be amplified when the tire contacts pot holes or irregularities in the road surface. Wander Wander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down a level road. Symptom Chart Symptom Chart Condition Possible Sources Action communication with the Circuit. GO to Pinpoint Test A. front electronic module FEM. (FEM) Unable to enter self-test FEM. GO to Pinpoint Test A. Diagnostic tool. Hard steering or lack of assist Seized lower steering column INSTALL a new lower (no DTCs present) shaft U-joints. steering column shaft. REFER to Steering Column in this Damaged, fractured steering INSTALL a new steering column bearing(s). column. REFER to Steering Column in this Power steering pump. GO to Component Tests, Pump Flow and Pressure Test in this Suspension components. REFER to Section for suspension system diagnosis and testing. Steering gear internal leakage. GO to Component Tests, Pump Flow and Pressure Test in this VAPS circuits 8-CE9 GO to Pinpoint Test D. (WH/GN), 9-CE9 (BN/GN). Steering system noise Low fluid level. GO to Pinpoint Test E. Fluid aeration. Steering gear. Power steering pump. Loose or damaged steering linkage. Loose or damaged suspension component(s). Steering column. Steering column boot bearing. Intermediate shaft. Loose dash boot seal.

7 Steering System Symptom Chart (Continued) Condition Possible Sources Action Steering is very difficult/very Seized intermediate shaft GO to Pinpoint Test F. easy U-joints. Damaged, fractured steering column bearing(s). Steering gear. Power steering pump. Power steering hoses. Binding dash boot seal. Excessive steering wheel play Steering gear. GO to Pinpoint Test G. Steering column. Steering column intermediate shaft. Steering linkage. Ball joints. Steering system Tire pressure. CORRECT the vehicle drift/pull/wander Wheel alignment. loading as necessary. GO to Steering gear. Pinpoint Test H. Unevenly loaded vehicle. Steering column intermediate shaft. Frame alignment. Feedback Loose, worn or damaged GO to Component Tests, tie-rod. Tie-Rod Articulation Torque in this Loose, worn or damaged GO to Component Tests, tie-rod ends. Steering Linkage in this Loose or damaged steering INSTALL new steering gear gear insulators or bolts. insulators or bolts if necessary, or TIGHTEN the bolts as needed. Loose lower steering column INSTALL new lower steering shaft U-joint or pinch bolts. column shaft and bolts or TIGHTEN the bolts. REFER to Steering Column in this Loose suspension bushings, INSTALL new as necessary. fasteners,ball joints, or strut REFER to Section bearing plate (if applicable). Worn or damaged steering INSTALL new steering column bearing(s). column bearings(s). REFER to Steering Column in this

8 Steering System Symptom Chart (Continued) Condition Possible Sources Action Poor returnability/sticky Binding lower steering INSTALL a new lower steering column shaft U-joints. steering column shaft. REFER to Steering Column in this Loose, worn or damaged GO to Component Tests, front wheel knuckle tie-rod. Tie-Rod Articulation Torque in this Loose, worn or damaged GO to Component Tests, tie-rod ends. Steering Linkage in this Suspension components. REFER to Section for the suspension diagnoses and testing. Binding steering column INSTALL new steering bearing(s). column bearings(s). REFER Binding dash boot seal. to Steering Column in this Shimmy Loose, worn or damaged GO to Component Tests, tie-rod end. Steering Linkage in this Loose, worn or damaged GO to Component Tests, tie-rod. Connector Reference and Terminal Readings Tie-Rod Articulation Torque in this Suspension components. REFER to Section for the suspension diagnosis and testing. Front Electronic Module (FEM)-C201a Pin Number(s) Circuit Designation/Description rmal Condition/Measurement 1 29S-DK21 (OG/WH) power supply to FEM Greater than 10 volts at all times. from BJB Fuse 30 (10A) 2 9-CE9 (BN/GN) VAPS solenoid feedback Voltage varies with VAPS solenoid position. signal (to FEM module) 9 8-CE9 (WH/GN) VAPS solenoid input signal Voltage varies with FEM module output from 1 to 12 volts.

9 Steering System Front Electronic Module (FEM)-C201b Pin Number(s) Circuit Designation/Description rmal Condition/Measurement 21 31S-DK21 (BK/WH) rear battery junction 0 voltage, less than 5 ohms to ground. box (RBJB) relay 32 coil ground VAPS Solenoid-C120 Pin Number(s) Circuit Designation/Description rmal Condition/Measurement 1 8-CE9 (WH/GN) VAPS solenoid input signal Voltage varies with FEM module output from 1 to 12 volts. 2 9-CE9 (BN/GN) VAPS solenoid feedback Voltage varies with VAPS solenoid position. signal (to FEM module) Pinpoint Test A: Communication With The FEM Module/Unable To Enter Self-Test rmal Operation The FEM module operates at a voltage between 10 and 17 volts. Voltage is supplied by circuit 29S-DK21 (OG/WH) (B+ at all times). RBJB relay 32 coil ground is provided through circuit 31S-DK21 (BK/WH). Possible Causes RBJB relay 32 coil ground circuit 31S-DK21 (BK/WH) RBJB relay 32 Relay 32 power-out circuit 30-DD2 (RD/BU) BJB fuse 30 (10A) power supply circuit 29S-DK21 (OG/WH) FEM PINPOINT TEST A: NO COMMUNICATION WITH THE FEM MODULE/UNABLE TO ENTER SELF-TEST A1 CAUTION: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes. CHECK BJB FUSE 30 (5A) Check BJB fuse 30 (5A). Yes Is the fuse OK? GO to A2. (Continued)

10 Steering System PINPOINT TEST A: NO COMMUNICATION WITH THE FEM MODULE/UNABLE TO ENTER SELF-TEST (Continued) A1 A2 A3 CHECK BJB FUSE 30 (5A) (Continued) INSTALL a new fuse. REPEAT the self-test. CHECK THE VOLTAGE TO THE FEM MODULE Key in OFF position. Disconnect: FEM Module C201a. Yes Key in ON position. GO to A3. Measure the voltage between FEM module C201a-1 circuit 29S-DK21 (OG/WH), harness side and ground REPAIR circuit 29S-DK21 (OG/WH). Is the voltage greater than 10 volts? REPEAT the self-test. CHECK THE RBJB RELAY 32 COIL GROUND Key in OFF position. Yes Measure the resistance between FEM module C201b-21, circuit CHECK the DLC connector and wiring. 31S-DK21 (BK/WH), harness side, and ground. REFER to Section Is the resistance less than 5 ohms? REPAIR circuit 31S-DK21 (BK/WH). REPEAT the self-test. Pinpoint Test B: DTC 1924 VAPS Solenoid Actuator Output Short To Ground rmal Operation The FEM module sends the VAPS solenoid a pulse width modulated (PWM) circuit through circuit 8-CE9 (WH/GN). The VAPS solenoid sends a feedback voltage to the FEM module, (depending on power steering assist demand), through circuit 9-CE9 (BN/GN). Possible Causes VAPS solenoid circuit 8-CE9 (WH/GN) PINPOINT TEST B: DTC 1924 VAPS SOLENOID ACTUATOR OUTPUT SHORT TO GROUND B1 B2 B3 CAUTION: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes. ISOLATE THE VAPS SOLENOID Raise and support the vehicle. For additional information, refer Yes tosection GO to B2. Disconnect: VAPS Solenoid C120. Measure the resistance across the VAPS solenoid C120, INSTALL a new VAPS solenoid. REFER terminals 1 and 2, component side. to Steering Gear in this CLEAR Is the resistance approximately 6 to 8 ohms? the DTC. REPEAT the self-test. CHECK CIRCUITS 8-CE9 (WH/GN) FOR A SHORT TO GROUND Measure the resistance between VAPS solenoid C120-1 circuit Yes 8-CE9 (WH/GN) harness side and ground. GO to B3. Is the resistance greater than 10,000 ohms? REPAIR circuit 8-CE9 (WH/GN). CLEAR the DTC. REPEAT the self-test. CHECK CIRCUITS 8-CE9 (WH/GN) AND VAPS SOLENOID FOR A SHORT TO GROUND Measure the resistance between VAPS solenoid C120-1 circuit Yes 8-CE9 (WH/GN) component side and ground. CARRY OUT the FEM diagnosis. Refer to Is the resistance greater than 10,000 ohms? Section CLEAR the DTC. REPEAT the self-test. INSTALL a new VAPS solenoid. REFER to Steering Gear in this CLEAR the DTC. REPEAT the self-test.

11 Steering System Pinpoint Test C: DTC 1925 VAPS Solenoid Actuator Return Circuit Failure rmal Operation The FEM module sends the VAPS solenoid a pulse width modulated (PWM) current through circuit 8-CE9 (WH/GN). The VAPS solenoid sends a feedback voltage to the FEM module, (depending on power steering assist demand), through circuit 9-CE9 (BN/GN). Possible Causes VAPS solenoid circuit 8-CE9 (WH/GN) circuit 9-CE9 (BN/GN) PINPOINT TEST C: DTC 1925 VAPS SOLENOID ACTUATOR RETURN CIRCUIT FAILURE C1 C2 C3 C4 C5 C6 CAUTION: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes. ISOLATE THE VAPS SOLENOID With the vehicle in Neutral, position it on a hoist. For additional Yes information, refer tosection GO to C2. Disconnect: VAPS Solenoid C120. Measure the resistance across the VAPS solenoid C120, INSTALL a new VAPS solenoid. REFER terminals 1 and 2, component side. to Steering Gear in this CLEAR Is the resistance approximately 6 to 8 ohms? The DTC. REPEAT the self-test. CHECK CIRCUITS 8-CE9 (WH/GN) AND 9-CE9 (BN/GN) FOR A SHORT TO BATTERY Measure the voltage between VAPS solenoid C120-1 circuit Yes 8-CE9 (WH/GN) harness side and ground and between C120-2 REPAIR circuit 8-CE9 (WH/GN) or circuit circuit 9-CE9 (BN/GN) harness side and ground. 9-CE9 (BN/GN). CLEAR the DTC. Is voltage present? REPEAT the self-test. GO to C3. CHECK CIRCUIT 8-CE9 (WH/GN) FOR AN OPEN Disconnect: FEM Module C201a. Yes Measure the resistance between VAPS solenoid C120-1 circuit GO to C4. 8-CE9 (WH/GN) harness side and C201a-9 circuit 8-CE9 (WH/GN) harness side. REPAIR the open circuit(s). CLEAR the Is the resistance less than 5 ohms? DTC. REPEAT the self-test. CHECK CIRCUIT 9-CE9 (BN/GN) FOR AN OPEN Measure the resistance between VAPS solenoid C120-2 circuit Yes 9-CE9 (BN/GN) harness side and C201a-2 circuit 9-CE9 GO to C5. (BN/GN) harness side. Is the resistance less than 5 ohms? REPAIR circuit 9-CE9 (BN/GN). CLEAR the DTC. REPEAT the self-test. CHECK CIRCUIT 9-CE9 (BN/GN) FOR A SHORT TO GROUND Measure the resistance between VAPS solenoid C120-2 circuit Yes 9-CE9 (BN/GN) component side and ground. GO to C6. Is the resistance greater than 10,000 ohms? REPAIR circuit 9-CE9 (BN/GN). CLEAR the DTC. REPEAT the self-test. CHECK CIRCUIT 9-CE9 (BN/GN) AND VAPS SOLENOID FOR A SHORT TO GROUND Measure the resistance between VAPS solenoid C120-2 circuit Yes 9-CE9 (BN/GN) component side and ground. CARRY OUT the FEM diagnosis. REFER Is the resistance greater than 10,000 ohms? to Section CLEAR the DTC. REPEAT the self-test. INSTALL a new VAPS solenoid. REFER to Steering Gear in this CLEAR the DTC. REPEAT the self-test.

12 Steering System Pinpoint Tests D: Hard Steering/Lack of Assist With DTCs rmal Operation The VAPS system provides power assist to steering input by multiplying the turning force applied at the steering wheel. When the vehicle is at rest or at a speed below 3.2 km/h (2 mph), the VAPS system supplies maximum assist. Between 3.2 km/h (2 mph) and 191 km/h (119 mph), power assist will decrease gradually at a calibrated rate to raise steering efforts for increased directional stability and greater road feel. Above 191 km/h (119 mph), steering assist is constant. Possible Causes circuit 8-CE9 (WH/GN) circuit 9-CE9 (BN/GN) VAPS solenoid D1 D2 PINPOINT TEST D: HARD STEERING/LACK OF ASSIST WITH NO DTCS CHECK CIRCUIT 8-CE9 (WH/GN) AND 9-CE9 (BN/GN) FOR SHORT A TOGETHER Disconnect: VAPS Solenoid C120. Yes Measure the resistance between VAPS solenoid C120-1 circuit GO to D2. 8-CE9 (WH/GN) and C120-2 circuit 9-CE9 (BN/GN) harness side. REPAIR the circuits. TEST the system for Is the resistance greater than 10,000 ohms? normal operation. CHECK THE STABILITY ASSIST MODULE Measure the resistance between VAPS solenoid C120-1 circuit Yes 8-CE9 (WH/GN) and C120-2 circuit 9-CE9 (BN/GN) component CARRY OUT the FEM diagnosis. REFER side. to Section TEST the system for Is the resistance greater than 10,000 ohms? normal operation. INSTALL a new VAPS solenoid. TEST the system for normal operation. Pinpoint Test E: Steering System ise rmal Operation The power steering pump, which is driven by the crankshaft through a drive belt and pulleys, develops the hydraulic pressure necessary to operate the system. When the engine is running, fluid is drawn into the power steering pump from the power steering pump reservoir. Hydraulic fluid is pressurized in the power steering pump and sent to the steering gear. The rotary valve determines fluid direction to assist the driver in the turning of the vehicle. When the steering wheel is turned, the steering gear converts this hydraulic pressure and flow into mechanical motion that will move the front wheels in the direction of the turn. The steering gear uses tie rod ends to connect the front knuckles, which then pivot on the ball joints, steering the vehicle. Possible Causes front suspension components power steering fluid level power steering pump steering column steering column boot steering gear steering linkage drive belt belt tensioner

13 Steering System PINPOINT TEST E: STEERING SYSTEM NOISE E1 CHECK FOR MECHANICAL NOISE Test drive the vehicle to verify the steering system noise. Yes Does the steering system make a clunk noise? CHECK for loose, worn or damaged tie rod ends. REFER to Component Tests, Steering Linkage in this CHECK for loose or worn steering gear isolators (if applicable). INSTALL new isolators if necessary. REFER to Steering Gear in this If the noise is from the steering column, CHECK the steering column intermediate shaft for grounding through the body and repair as necessary. If the noise is from the steering column boot bearing, INSTALL a new steering column boot bearing. REFER to Steering Column in this If the noise is from the suspension components, INSTALL new suspension components as necessary. REFER to Section If the noise is from loose, worn or damaged intermediate shaft U-joint(s), INSTALL a new lower steering column shaft. REFER to Steering Column in this If a squeak is present in the steering column, REPAIR the steering column mountings or align the steering column as necessary. REFER to Steering Column in this For all other concerns, GO to E2. (Continued)

14 Steering System E2 E3 E4 PINPOINT TEST E: STEERING SYSTEM NOISE (Continued) VERIFY THE CONCERN NOTE: Make sure that the vehicle is on a flat dry surface, the Yes transmission is in PARK, and that the windows are rolled up. If a grunt noise is present, verify the NOTE: Some power steering noise is expected. If in doubt of the steering column boot is OK and the acceptability of the noise level, evaluate another vehicle of the exhaust system is not grounding out. same model and powertrain. If a moan is present, verify that the tie rod Key in START position. ends and ball joints are OK. Turn the steering wheel one-half turn off-center to the right then GO to E3. one-half turn off-center to the left. Is the power steering noisy? If a squeal is present, INSPECT and INSTALL a new engine drive belt or belt tensioner as necessary. REFER to Section If the steering system noise is a hiss or whistle, INSPECT the steering column boot at the dash panel. REPAIR or INSTALL a new boot as necessary. REFER to Steering Column in this INSPECT the steering gear input shaft and valve for wear or damage. REFER to Steering Gear in this INSPECT the power steering gear, intermediate shaft and power steering lines and hoses for grounding to the body and repair as necessary. INSPECT for openings or missing plugs in the instrument panel cowl and repair as necessary. If there are no missing plugs or openings in the cowl, grounded power steering gear, intermediate shaft or power steering lines or hoses, GO to E6. CHECK FOR COLD START NOISE NOTE: Some noise during an extremely cold start C (-14 F) Yes is normal and should improve as the steering system warms up CHECK for contamination in the power (usually within 60 seconds). steering reservoir screen. FLUSH the Key in START position. power steering system as necessary. Verify the noise condition. REFER to Power Steering System Is the noise present only during cold start up? Flushing in this TEST the system for normal operation. GO to E4. INSPECT THE POWER STEERING FLUID Key in OFF position. Yes With the engine OFF, inspect the power steering fluid for GO to E5. aeration. Is the power steering fluid foamy or aerated? PURGE the power steering system. REFER to Power Steering System Purging in this If a whine or a moan is still present, INSTALL a new power steering pump. REFER to Power Steering Pump in this If the power steering noise is a grunt, INSTALL a new power steering gear. REFER to Steering Gear in this (Continued)

15 Steering System E5 E6 PINPOINT TEST E: STEERING SYSTEM NOISE (Continued) CHECK THE POWER STEERING FLUID LEVEL WITH THE ENGINE ON AND OFF NOTE: Record the vacuum level when the pump noise occurs with no steering input. Vacuum level should be greater than 10 inches of mercury with CII pump and 15 inches of mercury on the CIII pump. Key in START position. Yes With the engine running, inspect the power steering fluid level. PURGE the power steering system. Key in OFF position. REFER to Power Steering System Purging With the engine off, inspect the power steering fluid level. in this Does the power steering fluid level change with the engine off? GO to E6. CHECK THE POWER STEERING PUMP NOTE: Do not turn the steering wheel to either the right or left stop. Power steering relief noise will occur and is normal at the stop Yes positions. INSTALL a new power steering gear. Key in START position. REFER to Steering Gear in this With the engine running, rotate the steering wheel 90 degrees to the left then to the right. INSTALL a new power steering pump. Does the frequency of the hiss change between the left and REFER to Power Steering Pump in this right positions? Pinpoint Test F: Steering is Very Difficult/Very Easy rmal Operation The power steering pump, which is driven by the crankshaft through a drive belt and pulleys, develops the hydraulic pressure necessary to operate the system. When the engine is running, fluid is drawn into the power steering pump from the power steering pump reservoir. Hydraulic fluid is pressurized in the power steering pump and sent to the steering gear. The rotary valve determines fluid direction to assist the driver in the turning of the vehicle. When the steering wheel is turned, the steering gear converts this hydraulic pressure and flow into mechanical motion that will move the front wheels in the direction of the turn. The steering gear uses tie rod ends to connect the front knuckles, which then pivot on the ball joints, steering the vehicle. Possible Causes intermediate shaft intermediate shaft U-joints steering column steering column bearings steering gear power steering pump power steering hoses ball joints F1 PINPOINT TEST F: STEERING IS VERY DIFFICULT/VERY EASY CHECK THE STEERING COLUMN BEARINGS AND THE INTERMEDIATE SHAFT NOTE: Be sure to keep the clockspring centered when Yes disconnecting the intermediate shaft. Refer to Section B. GO to F2. Check the steering column and intermediate shaft for grounding. Disconnect the steering column intermediate shaft at the If the steering column or the intermediate steering column. shaft are grounding, repair as necessary. Verify that the intermediate shaft universal joints do not bind and move freely and that the steering column bearing rotates freely. If the steering column bearings or the Are the steering column bearing and intermediate shaft intermediate shaft are binding. INSTALL a universal joints OK? new intermediate shaft or steering column. REFER to Steering Column in this (Continued)

16 Steering System F2 F3 PINPOINT TEST F: STEERING IS VERY DIFFICULT/VERY EASY (Continued) CHECK THE FRONT BALL JOINTS Check that the front ball joints move freely and are not binding Yes or sticking. Refer to Section GO to F3. Are the front ball joints OK? INSTALL new ball joints as necessary. REFER to Section MONITOR ENGINE RPM CHANGES NOTE: Make sure that the vehicle is on a flat dry surface. Yes Key in START position. If no power steering assist is present and the engine rpm changes, INSTALL a new CAUTION: Do not hold the steering wheel at the steering gear. REFER to Steering Gear in stops for an extended amount of time. Damage to the power this steering pump can occur. If left-to-right variation is present, INSTALL Turn the steering wheel once to the left stop position and then to a new steering gear. REFER to Steering the right stop position. Gear in this te the engine rpm during the turns. Does the engine rpm change when turning the steering If no power steering assist is present and wheel? the engine rpm does not change, INSTALL a new power steering pump. REFER to Power Steering Pump in this If excessive effort is required in one or both directions, INSTALL a new power steering pump. REFER to Power Steering Pump in this CARRY OUT the Pump Flow and Pressure Test. REFER to Component Tests in this Pinpoint Test G: Excessive Steering Wheel Play rmal Operation When the steering wheel is turned, the steering shaft rotates in the steering column on bearings. This mechanical motion is then converted to hydraulic pressure that reduces assists in the effort that it takes to steer the vehicle. This hydraulic pressure from the power steering pump to the power steering gear is then converted back to mechanical motion that will move the front wheels in the direction of the turn. The steering gear uses tie rod ends to connect the front knuckles to one another. The knuckles then pivot on the ball joints in order to steer the vehicle. Possible Causes steering column bearing steering linkage suspension components G1 PINPOINT TEST G: EXCESSIVE STEERING WHEEL PLAY CHECK THE STEERING COLUMN BEARING Inspect the steering column mounting fasteners and bearing for Yes looseness. GO to G2. Are the fasteners and bearing OK? TIGHTEN the steering column mounting fasteners or INSTALL a new steering column. REFER to Steering Column in this (Continued)

17 Steering System G2 PINPOINT TEST G: EXCESSIVE STEERING WHEEL PLAY (Continued) CHECK THE STEERING LINKAGE FOR LOOSENESS Carry out the Steering Linkage component test. Refer to Yes Component Tests in this REFER to Section to diagnose Is the steering linkage OK? the suspension components. INSTALL new steering linkage as necessary. REFER to Steering Gear in this Pinpoint Test H: Steering System Drift/Pull/Wander rmal Operation When the steering wheel is turned, the steering shaft rotates in the steering column on bearings. This mechanical motion is then converted to hydraulic pressure that reduces assists in the effort that it takes to steer the vehicle. This hydraulic pressure from the power steering pump to the power steering gear is then converted back to mechanical motion that will move the front wheels in the direction of the turn. The steering gear uses tie rod ends to connect the front knuckles to one another. The knuckles then pivot on the ball joints in order to steer the vehicle. Possible Causes steering gear intermediate shaft intermediate shaft U-joints steering gear mounts suspension components H1 H2 H3 PINPOINT TEST H: STEERING SYSTEM DRIFT/PULL/WANDER CHECK FOR TIRE PULL Rotate the front wheel and tire assemblies side-to-side. Refer to Yes Section If vehicle pulls in the opposite direction, Carry out a road test on a smooth, flat road. GO to H2. Does the vehicle drift/pull? If vehicle pulls in original direction, GO to H3. Concern has been corrected. ROTATE THE WHEEL AND TIRE ASSEMBLIES FRONT TO REAR Rotate the front wheel and tire assemblies front to rear. Refer to Yes Section GO to H3. Carry out a road test on a smooth, flat road. Does the vehicle drift/pull? Concern has been corrected. CHECK THE STEERING COLUMN INTERMEDIATE SHAFT NOTE: Be sure to keep the clockspring centered when disconnecting the intermediate shaft. Refer to Section B. Check the steering column and intermediate shaft for grounding. Disconnect the steering column intermediate shaft at the Yes steering column. GO to H4. Inspect the steering column intermediate shaft U-joints for looseness or wear. INSTALL a new steering column Are the steering column intermediate shaft universal joints intermediate shaft. REFER to Steering OK? Column in this (Continued)

18 Steering System H4 H5 H6 H7 PINPOINT TEST H: STEERING SYSTEM DRIFT/PULL/WANDER (Continued) CHECK THE STEERING GEAR MOUNTING Check the steering gear mounts for looseness or wear. Yes Are the steering gear mounts OK? GO to H5. INSTALL new steering gear mounts. REFER to Steering Gear in this CHECK THE STEERING GEAR Carry out the Steering Gear Valve component test. Refer to Yes Component Tests in this GO to H6. Is the steering gear valve OK? REPAIR or INSTALL a new steering gear. REFER to Steering Gear in this CHECK THE SUSPENSION COMPONENTS Check for loose or worn suspension components. Refer to Yes Section GO to H7. Are the suspension components OK? INSTALL new suspension components. REFER to Section CHECK THE WHEEL ALIGNMENT NOTE: The vehicle will tend to pull toward the side with the least Yes positive caster and the most positive camber. CHECK for correct frame alignments. Using a suitable alignment system, measure the wheel REFER to Section alignment settings. Refer to Section Are the alignment settings within specifications? ADJUST the alignment angles to specifications. DO NOT exceed specifications. TEST the system for normal operation. Component Tests 3. NOTE: Incorrect separation of the tapered stud Steering Linkage from its seat will cause premature failure of the ball socket. 1. NOTE: Excessive vertical motion of the studs Joints can be checked for excessive wear by relative to the sockets may indicate excessive measuring the torque it takes t turn the stud. wear. 1 Separate the tapered stud from its seat and With the vehicle on the ground and the parking thread the attaching nut back onto the stud. brake applied, start the vehicle and carry out the following: 2 NOTE: Some joint turning torques will be as little as 0.2 Nm (2.0 lb-in) within the Have an assistant rotate the steering wheel first 1,600 km (1,000 miles) and will remain back and forth 360 degrees and watch for there for the life of the joint. relative motion of the studs in the steering linkage ball sockets. Turn the stud with an inch-pound torque wrench and note the torque required to turn Watch for loose steering gear mounting. the stud. 2. An additional check is with the KOEO and the front wheels raised off the ground, grasp the Torque Required to Turn Stud wheel at the front and rear and watch for in Socket excessive play or binding in the joints while Nm Lb-In trying to steer the wheels. New joints Used joints Joints with Less than 0.2 Less than 2.0 excessive play 4. Install new components if necessary. Tighten any worn, damaged, or loose components.

19 Steering System Turning Effort Test 5. CAUTION: Do not hold the steering NOTE: Make sure that the front wheels are wheel against the stops for more than 3 to 5 correctly aligned and the tire pressure is correct seconds at a time. Damage to the power before checking the steering effort. steering pump can occur. 1. Park the vehicle on dry concrete and set the Start the engine. Place the transmission in parking brake. NEUTRAL. Set the parking brake. Raise the 2. Insert a thermometer into the power steering oil power steering fluid temperature to C reservoir. ( F) by rotating the steering wheel fully to the left and right several times. 3. CAUTION: Do not hold the steering 6. With the steering wheel in the straight-ahead wheel against the stops for more than 3 to 5 position, set the engine speed to 2,100 rpm. seconds at a time. Damage to the power Record the flow rate and pressure readings. steering pump can occur. If the flow rate is below the flow rate Idle the engine for 2 to 3 minutes. Turn the specification, continue with the test steering wheel from stop-to-stop several times procedure. to warm the fluid to C ( F). If the pressure reading is above the 4. With the engine running, attach the spring scale maximum pressure specification, check the to the rim of the steering wheel. power steering hoses for kinks and 5. Measure the pull required to turn the steering restrictions. wheel one complete revolution in each 7. Partially close the gate valve to obtain 750 psi. direction. Refer to General Specifications, Set the engine speed at idle. Record the flow Steering Wheel Turning Effort in this rate. Pump Flow and Pressure Test If the flow is less than the specified flow WARNING: Do not touch the flowmeter rate, install a new power steering pump. during the test procedure, or severe burns and 8. CAUTION: Do not allow the gate valve serious injury can occur. Failure to follow these to remain closed for more than 5 seconds. instructions may result in personal injury. Completely close and partially open the gate 1. CAUTION: Make sure that the valve 3 times. Record the pressure relief valve connection point will not interfere with any actuation pressure reading. of the engine accessory drive components or If the pressure does not meet the relief drive belts. pressure specification, then install a new Install the power steering analyzer at the high power steering pump. pressure port of the power steering pump. Make 9. Set engine speed to 2,100 rpm. Record the flow sure the power steering analyzer gate valve is rate. fully open. If the flow rate varies more than Place a dial thermometer in the power steering liters/minute (1 gallon/minute) from the pump reservoir. initial flow rate reading, install a new power steering pump. 3. Check the power steering fluid level. If necessary, add specified power steering fluid. 4. Install a digital tachometer.

20 Steering System CAUTION: Do not hold the steering 2. Move the front wheel knuckle tie-rod back and wheel against the stops for more than 3 to 5 forth three times. seconds at a time. Damage to the power 3. Hook a spring scale over the tie-rod end, or the steering pump can occur. threaded portion of the front wheel knuckle Set the engine speed at idle. Turn (or have an tie-rod, and measure the force required to move assistant turn) the steering wheel to the left and the front wheel knuckle tie-rod. Refer to right stops. Record flow rate and pressure General Specifications, Tie-Rod Articulation readings at the stops. Torque in this The pressure reading at both stops should be 4. If the force required to move the front wheel nearly the same as the maximum pump knuckle tie-rod does not meet the specifications, relief pressure. install a new front wheel knuckle tie-rod. Refer to Steering Gear in this The flow rate should drop below 1.9 liters/minute (0.5 gallons/minute). Steering Gear Valve If the pressure does not reach the maximum 1. With the vehicle in motion, place the pump relief pressure or the flow rate does transmission in NEUTRAL and turn the engine not drop below the specified value, OFF. excessive internal leakage is occurring. If the vehicle does not pull with the engine Install a new steering gear as necessary. OFF, repair or install a new steering gear. Refer to Steering Gear in this Refer to Steering Gear in this 11. Turn (or have an assistant turn) the steering 2. If the vehicle pulls with the engine OFF, switch wheel slightly in both directions and release the right side front wheel to the left side of the quickly while watching the pressure gauge. vehicle and the left side front wheel to the right The pressure reading should move from the side of the vehicle. normal back pressure reading and snap back 3. If the vehicle pulls to the opposite side, switch as the steering wheel is released. the front wheels with the rear wheels keeping If the pressure returns slowly or sticks, the them on the same side of the vehicle. rotary valve in the steering gear is sticking 4. If the vehicle pull direction does not change, or the steering column is binding. Check the check the front suspension components, wheel steering column and linkages before alignment and frame alignment. Refer to repairing the steering gear. Section or an appropriate frame Tie-Rod Articulation Torque dimensions manual. NOTE: This check may be done with the steering gear on or off the vehicle. 1. Disconnect the tie-rod-end from the front wheel knuckle. Refer to Steering Gear in this