ENGINE 1UZ-FE ENGINE 45 ENGINE CONTROL SYSTEM 1. General The engine control system of the new 1UZ-FE engine is basically same in construction and operation as that of the 1UZ-FE engine for the 98 LS400. The fuel pump speed control has been changed from 2 steps to 3 steps. Comparison of the engine control system between the 1UZ-FE engine for the new GS400 and 98 LS400. System Outline GS400 98 LS400 SFI A L-type SFI system directly detects the intake air vol- Sequential ume with a hot-wire type mass air flow meter. Multiport Fuel The fuel injection system is a sequential multiport fuel Injection injection system. ESA Electronic Spark Advance VVT-i Valiable Valve Timing-intelligent ETCS-i Electronic Throttle Control Systemintelligent ACIS Acoustic Control Induction System Fuel Pump Control Oxygen Heater Control Air Conditioning Cut-Off Control Evaporative Emission Control Ignition timing is determined by the based on signals from various sensors. Corrects ignition timing in response to engine knocking. The torque control correction during gear shifting has been used to minimize the shift shock. 2 knock sensors are used to further improve knock detection. Controls the intake camshaft to an optimal valve timing in accordance with the engine condition. Optimally controls the throttle valve opening in accordance with the amount of the accelerator pedal effort, and the conditions of the engine and the vehicle, and comprehensively controls the ISC, cruise control, and the VSC system. The intake air passages are switched according to the engine speed and throttle valve opening angle to provide high performance in all speed ranges. 2-steps control by a fuel Under light engine loads, pump relay and a fuel pump speed is low to re- pump resister. duce electric power loss. 3-steps control by fuel pump ECU Maintains the temperature of the oxygen sensor at an appropriate level to increase accuracy of detection of the oxygen concentration in the exhaust gas. By controlling the air conditioning compressor ON or OFF in accordance with the engine condition, drivability is maintained. The controls the purge flow of evaporative emissions (HC) in the charcoal canister in accordance with engine conditions. (Continued)
46 ENGINE 1UZ-FE ENGINE System Outline GS400 98 LS400 Engine Immobiliser Function to communicate with multiplex communication system Diagnosis Fail-Safe Prohibits fuel delivery and ignition if an attempt is made to start the engine with an invalid ignition key. Communicates with the body ECU, A/C ECU, etc., on the body side, to input/output necessary signals. When the detects a malfunction, the diagnoses and memorizes the failed section. The diagnosis system includes a function that detects a malfunction in the evaporative emission control system. When the detects a malfunction, the stops or controls the engine according to the data already stored in the memory.
ENGINE 1UZ-FE ENGINE 47 2. Construction The configuration of the engine control system in the 1UZ-FE engine of the GS400 is as shown in the following chart. SENSORS MASS AIR FLOW METER CRANKSHAFT POSITION SENSOR Engine Speed Signal Crankshaft Angle Signal CAMSHAFT POSITION SENSOR Crankshaft Angle Signal VVT SENSOR Camshaft Position Signal THROTTLE POSITION SENSOR Throttle Position Signal ACCELERATOR PEDAL POSITION SENSOR Accelerator Pedal Position Signal ENGINE COOLANT TEMP. SENSOR INTAKE AIR TEMP. SENSOR HEATED OXYGEN SENSOR (Bank 1, 1) HEATED OXYGEN SENSOR (Bank 2, 1) HEATED OXYGEN SENSOR (Bank 1, 2) HEATED OXYGEN SENSOR (Bank 2, 2) KNOCK SENSORS VEHICLE SPEED SENSOR VG NE G2 VVL VVR VTA VTA2 VPA VPA2 THW THA OXL1 OXR1 OXL2 OXR2 KNKL KNKR SP2 BARO (Intergrated) #10 #20 #30 #40 #50 #60 #70 #80 IGT1,4,6,7 IGF1 IGT2,3,5,8 IGF2 M CL OCV OCR ACIS ACTUATORS SFI No. 1 INJECTOR No. 2 INJECTOR No. 3 INJECTOR No. 4 INJECTOR No. 5 INJECTOR No. 6 INJECTOR No. 7 INJECTOR No. 8 INJECTOR ESA IGNITION COIL with IGNITER Nos. 1, 4, 6 and 7 IGNITION COIL with IGNITER Nos. 2, 3, 5 and 8 SPARK PLUGS Nos. 2, 3, 5 and 8 ETCS-i SPARK PLUGS Nos. 1, 4, 6 and 7 THROTTLE CONTROL MOTOR MAGNET CLUTCH VVT-i CAMSHAFT TIMING OIL CONTROL VALVE (Bank 1) CAMSHAFT TIMING OIL CONTROL VALVE (Bank 2) ACIS IGNITION SWITCH Starting Signal (ST Terminal) Ignition Signal (IG Terminal) PARK/NEUTRAL POSITION SWITCH Neutral Start Signal Shift Lever Position Signal STA IGSW P, N R,D,4,3,2,L FPC DI ACMG FUEL PUMP CONTROL FUEL PUMP ECU FUEL PUMP AIR CONDITIONING CONTROL AIR CONDITIONING MAGNET CLUTCH (Continued)
48 ENGINE 1UZ-FE ENGINE AIR CONDITIONING ECU MPX1 OXYGEN SENSOR HEATER CONTROL BODY ECU MPX2 HTL HTR (Bank 1, 1) (Bank 2, 1) STOP LIGHT SWITCH VAPOR PRESSURE SENSOR STP PTNK HTL2 HTR2 (Bank 1, 2) (Bank 2, 2) ABS & TRAC & VSC ECU TRC ENG PRG EVAP CONTROL TRANSPONDER KEY AMPLIFIER TXCT RXCK CODE TPC VAPOR PRESSURE CONTROL UNLOCK WARNING SWITCH KSW IMLD THEFT DETERRENT INDICATOR LIGHT DATA LINK CONNECTOR 1 TC MREL EFI MAIN RELAY DATA LINK CONNECTOR 3 SIL W MALFUNCTION INDICATOR LAMP +B BATT, BM EFI MAIN RELAY BATTERY
3. Engine Control System Diagram ENGINE 1UZ-FE ENGINE 49 Ignition Switch Fuel Pump ECU for Vapor Pressure Vapor Pressure Intake Air Temp. Mass Air Flow Meter Fuel Pump Charcoal Canister Throttle Position Camshaft Timing Oil Control Valve Camshaft Position VVT Igniter Throttle Control Motor * 1 Accelerator Pedal Position (for EVAP) (for ACIS) Camshaft Timing Oil Control Valve VVT Igniter Knock Knock Crankshaft Position Battery MIL DLC1 DLC3 Air Conditioner Starter Vahicle Speed * 1 : Engine Coolant Temp. : Heated Oxygen Park/Neutral Position 152EG17
50 Throttle Position Mass Air Flow Meter Accelerator Pedal Position Camshaft Timing Oil Control Valve Engine Coolant Temp. VVT (Bank 2) (for ACIS) Ignition Coil (with Igniter) Knock VVT (Bank 1) Park/Neutral Position Switch Fuel Pump ECU for Vapor Pressure Vapor Pressure 4. Layout of Components ENGINE 1UZ-FE ENGINE Throttle Control Motor DLC 3 Camshaft Position Crankshaft Position Camshaft Timing Oil Control Valve DLC 1 (for EVAP) Heated Oxygen (Bank 2, 1) Heated Oxygen (Bank 1, 1) Heated Oxygen (Bank 1, 2) Heated Oxygen (Bank 2, 2) 152EG13
ENGINE 1UZ-FE ENGINE 51 5. Main Components of Engine Control System General The following table compares the main components of the 1UZ-FE engine in the new GS400 and 98 LS400. Components 1UZ-FE Engine GS400 98 LS400 Mass Air Flow Meter Hot-Wire Type Crankshaft Position Pick-Up Coil Type, 1 Camshaft Position Pick-Up Coil Type, 1 VVT Pick-Up Coil Type, 2 Throttle Position Linear Type, 2 Accelerator Pedal Position Linear Type, 2 Knock Oxygen Built-In Piezoelectric Type, 2 Heated Oxygen (Bank 1, 1) (Bank 2, 1) (Bank 1, 2) (Bank 2, 2) 4-Hole Type with Air Assist Similar to the GS300 with the 2JZ-GE engine, the is installed in the engine compartment. The basic construction is the same as that of the 2JZ-GE engine. See page 39. 6. Fuel Pump Control The uses the fuel pump ECU to control the fuel pump speed in 3 steps. The basic operation is the same as that of the 2JZ-GE engine. See page 40.