Engine Control System (Service Information): Diagnosis Lexus GX J150

ON-VEHICLE INSPECTION

1. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY Connect the Techstream to the DLC3. Start the engine and turn the Techstream on. Warm up the engine. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1), Control the VVT Linear (Bank 2), Control the VVT System (Bank 1), Control the VVT System (Bank 2), Control the VVT Exhaust Linear (Bank 1) or Control the VVT Exhaust Linear (Bank 2). Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream. OK Tester Operation Specified Condition OCV OFF Normal engine speed OCV ON Soon after OCV switched from OFF to ON, engine idles roughly or stalls If the result is not as specified, check the oil control valve, wiring and camshaft timing gear. HINT: Control the VVT Linear (Bank 1): Command to activate the exhaust and intake side oil control valves of bank 1 (Control range: Between -128 and 127%). Control the VVT Linear (Bank 2): Command to activate the exhaust and intake side oil control valves of bank 2 (Control range: Between -128 and 127%). Control VVT System (Bank 1): Command to activate the oil control valve of bank 1 (Control range: ON/OFF). Control VVT System (Bank 2): Command to activate the oil control valve of bank 2 (Control range: ON/OFF). Control the VVT Exhaust Linear (Bank 1): Command to activate the exhaust side oil control valve of bank 1 (Control range: Between -128 and 127%). Control the VVT Exhaust Linear (Bank 2): Command to activate the exhaust side oil control valve of bank 2 (Control range: Between -128 and 127%).

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1. REMOVE V-BANK COVER SUB-ASSEMBLY . Refer to «REMOVAL - Step 15»(ref-524246-S36416482222013012800000)
2. REMOVE AIR CLEANER CAP AND HOSE . Refer to «REMOVAL - Step 23»(ref-524246-S36416482222013012800000)
3. REMOVE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (for Exhaust Side of Bank 1) Disconnect the camshaft timing oil control valve connector. Remove the bolt and camshaft timing oil control valve. Remove the O-ring from the camshaft timing oil control valve.
4. REMOVE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (for Intake Side of Bank 1) Disconnect the camshaft timing oil control valve connector. Remove the bolt and camshaft timing oil control valve. Remove the O-ring from the camshaft timing oil control valve.
5. REMOVE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (for Intake Side of Bank 2) Disconnect the camshaft timing oil control valve connector. Remove the bolt and camshaft timing oil control valve. Remove the O-ring from the camshaft timing oil control valve.
6. REMOVE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (for Exhaust Side of Bank 2) Disconnect the camshaft timing oil control valve connector. Remove the bolt and camshaft timing oil control valve. Remove the O-ring from the camshaft timing oil control valve.

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1. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 - 2 20°C (68°F) 6.9 to 7.9 ohms If the result is not as specified, replace the camshaft timing oil control valve assembly. Connect the positive (+) lead of the battery to terminal 1 and the negative (-) lead to terminal 2 and check the movement of the valve. OK Condition Specified Condition Battery positive (+) voltage is applied Valve moves in left arrow direction shown in the illustration Battery positive (+) voltage is cut off Valve moves in right arrow direction shown in the illustration TEXT IN ILLUSTRATION *a Component without harness connected (Camshaft Timing Oil Control Valve) If the result is not as specified, replace the camshaft timing oil control valve assembly. If the valve cannot return properly because of foreign matter, a small pressure leak in the advanced direction may occur and a DTC may be stored.

1. CHECK THROTTLE BODY ASSEMBLY Check the throttle control motor operating sounds. Turn the engine switch on (IG). When depressing the accelerator pedal, check the operating sound of the running motor. Make sure that no friction noises are emitted from the motor. If friction noise exists, replace the throttle body. Check the throttle position sensor. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Throttle Sensor Position. Depress the accelerator pedal. When the throttle valve is fully opened, check that the value of "Throttle Sensor Position" is within the specification. Standard throttle valve opening percentage 60% or more HINT: When checking the standard throttle valve opening percentage, the shift lever should be in N. If the percentage is less than 60%, replace the throttle body assembly.

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1. REMOVE LOWER FRONT BUMPER COVER . Refer to «REMOVAL - Step 6»(ref-524246-S36416482222013012800000)
2. REMOVE NO. 1 ENGINE UNDER COVER SUB-ASSEMBLY . Refer to «REMOVAL - Step 7»(ref-524246-S36416482222013012800000)
3. DRAIN ENGINE COOLANT . Refer to «REPLACEMENT - Step 5»(ref-524250-S32040211512013012800000)
4. REMOVE V-BANK COVER SUB-ASSEMBLY . Refer to «REMOVAL - Step 15»(ref-524246-S36416482222013012800000)
5. REMOVE AIR CLEANER CAP AND HOSE . Refer to «REMOVAL - Step 23»(ref-524246-S36416482222013012800000)
6. REMOVE THROTTLE BODY ASSEMBLY Disconnect the No. 4 water by-pass hose and No. 12 water by-pass hose. Disconnect the throttle position sensor and control motor connector. Remove the 4 bolts, throttle body and gasket. Remove the No. 12 water by-pass hose from the throttle body. Remove the No. 4 water by-pass hose from the throttle body.

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1. INSPECT THROTTLE BODY ASSEMBLY Check the throttle valve. Check that the throttle valve opens and closes smoothly. Check that there is no sludge accumulating around the throttle body. Check the throttle control motor. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (M-) - 2 (M+) 20°C (68°F) 0.3 to 100 ohms TEXT IN ILLUSTRATION *a Component without harness connected (Throttle Body) If the result is not as specified, replace the throttle body assembly.

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1. INSTALL THROTTLE BODY ASSEMBLY Install the No. 4 water by-pass hose to the throttle body. TEXT IN ILLUSTRATION *1 Paint Mark HINT: When installing the hose, make sure the paint mark and clip are as shown in the illustration. Install the No. 12 water by-pass hose to the throttle body. TEXT IN ILLUSTRATION *1 Paint Mark HINT: When installing the hose, make sure the paint mark and clip are as shown in the illustration. Align the protrusion of a new gasket with the groove of the intake air surge tank and install the gasket to the intake air surge tank. TEXT IN ILLUSTRATION *1 Groove *2 Protrusion Install the throttle body with the 4 bolts. Torque: 10 N*m (102 kgf*cm, 7 ft.*lbf) Connect the throttle position sensor and control motor connector. Connect the No. 4 water by-pass hose and No. 12 water by-pass hose. TEXT IN ILLUSTRATION *1 Paint Mark *a Upper Side *b Lower Side *c 13 to 17 mm (0.511 to 0.669 in.) *d 5 mm (0.197 in.) HINT: When connecting the hoses, make sure the paint marks and clips are as shown in the illustration.
2. INSTALL AIR CLEANER CAP AND HOSE . Refer to «INSTALLATION - Step 53»(ref-524246-S15625075792013012800000)
3. ADD ENGINE COOLANT . Refer to «REPLACEMENT - Step 6»(ref-524250-S32040211512013012800000)
4. INSPECT FOR COOLANT LEAK . Refer to «ON-VEHICLE INSPECTION - Step 1»(ref-524249-S11423921442013012800000)
5. INSTALL NO. 1 ENGINE UNDER COVER SUB-ASSEMBLY . Refer to «INSTALLATION - Step 88»(ref-524246-S15625075792013012800000)
6. INSTALL LOWER FRONT BUMPER COVER . Refer to «INSTALLATION - Step 89»(ref-524246-S15625075792013012800000)
7. INSTALL V-BANK COVER SUB-ASSEMBLY . Refer to «INSTALLATION - Step 80»(ref-524246-S15625075792013012800000)
8. PERFORM INITIALIZATION NOTE: Be sure to perform this procedure after reassembling the throttle body assembly or removing and reinstalling any throttle body component. Perform the following procedure after replacing the ECM, throttle body assembly or any throttle body components. The following procedure should also be performed if the throttle body is cleaned. Be sure to perform this procedure after reconnecting the battery cable and replacing the ECM. Disconnect the EFI fuse, wait at least 60 seconds, and then reconnect the fuse. Turn the engine switch on (IG) without operating the accelerator pedal. NOTE: If the accelerator pedal is operated, perform the above steps again. Connect the Techstream to the DLC3 and clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-524126-S41645429092013012800000) . Start the engine and check that the MIL is not illuminated and that the idle speed is within the specified range when the A/C is switched off after the engine is warmed up. Standard Condition Engine Idle Speed A/C switched off 550 to 780 rpm NOTE: Be sure to perform this step with all accessories off. Make sure that the shift lever is in N or P. Enter the following menus: Powertrain / Engine and ETC / Data List / All Data / Throttle Sensor Position. Sensor Output. Fully depress the accelerator pedal and check that the value is 60% or more. Perform a road test and confirm that there are no abnormalities.

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1. REMOVE INSTRUMENT PANEL BOX ASSEMBLY Remove the instrument panel box. Refer to «REMOVAL»(ref-524278-S34089420712013012800000) .
2. REMOVE ECM Disconnect the 6 ECM connectors. Remove the bolt, nut and ECM.
3. REMOVE ECM BRACKET Remove the 2 screws and ECM bracket.
4. REMOVE NO. 2 ECM BRACKET Remove the 2 screws and No. 2 ECM bracket.

1. INSPECT ACCELERATOR PEDAL POSITION SENSOR Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Data List / ALL Date / Accel Sensor Out No. 1 and Accel Sensor Out No. 2. Read the value displayed on the Techstream. Standard Voltage Accel Sensor Out No. 1 Accel Sensor Out No. 2 Condition Specified Condition Accelerator pedal is released 0.5 to 1.1 V Accelerator pedal is depressed 2.6 to 4.5 V Condition Specified Condition Accelerator pedal is released 1.2 to 2.0 V Accelerator pedal is depressed 3.4 to 4.7 V If the result is not as specified, check the accelerator pedal position sensor, wire harness or ECM.

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1. REMOVE FRONT NO. 1 CONSOLE BOX INSERT . Refer to «REMOVAL - Step 3»(ref-524278-S34350614792013012800000)
2. REMOVE ACCELERATOR PEDAL POSITION SENSOR ASSEMBLY Disconnect the accelerator pedal position sensor connector. Remove the 2 nuts and accelerator pedal position sensor.

INSPECTION

1. INSPECT KNOCK SENSOR Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 - 2 20°C (68°F) 120 k to 280 kohms If the result is not as specified, replace the knock sensor.

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1. INSTALL KNOCK SENSOR Install the 4 knock sensors with the 4 bolts so that the knock sensors are angled as shown in the illustration. Torque: 20 N*m (204 kgf*cm, 15 ft.*lbf) TEXT IN ILLUSTRATION *A for Bank 2 Sensor 1 *B for Bank 1 Sensor 1 *C for Bank 2 Sensor 2 *D for Bank 1 Sensor 2 Front Upper Side Rear Connect the 4 knock sensor connectors.
2. INSTALL SEPARATOR CASE Install the separator case with the 4 bolts. Torque: 10 N*m (102 kgf*cm, 7 ft.*lbf)
3. INSTALL EGR COOLER ASSEMBLY Install the EGR cooler. Refer to «INSTALLATION»(ref-524251-S10974160662013012800000) .

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1. REMOVE V-BANK COVER SUB-ASSEMBLY . Refer to «REMOVAL - Step 15»(ref-524246-S36416482222013012800000)
2. REMOVE MANIFOLD ABSOLUTE PRESSURE SENSOR Disconnect the manifold absolute pressure sensor connector. Remove the bolt and manifold absolute pressure sensor. Remove the O-ring from the manifold absolute pressure sensor.

1. INSPECT POWER STEERING OIL PRESSURE SWITCH Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Power Steering Pressure. Start the engine. Operate the steering wheel while idling and read the value on the Techstream. Standard Measurement Condition Specified Condition Power steering not operating 0 to 2000 kPa (0 to 20 kgf/cm 2 , 0 to 290 psi) Power steering operating Value changes from value displayed when power steering not operating If the result is not as specified, check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-524126-S41645429092013012800000) . If the power steering system inspection results are normal and a DTC is not output, replace the power steering oil pressure switch.

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1. REMOVE FAN AND GENERATOR V BELT Remove the fan and generator V belt. Refer to «REMOVAL»(ref-524246-S10356726722013012800000) .
2. REMOVE FRONT WHEEL
3. REMOVE FRONT FENDER APRON SEAL RH . Refer to «REMOVAL - Step 11»(ref-524246-S36416482222013012800000)
4. DRAIN POWER STEERING FLUID
5. REMOVE POWER STEERING OIL PRESSURE SWITCH Disconnect the power steering oil pressure switch connector. Remove the power steering oil pressure switch. Remove the O-ring from the power steering oil pressure switch.

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1. INSTALL POWER STEERING OIL PRESSURE SWITCH Install a new O-ring to the power steering oil pressure switch. Apply a light coat of engine oil to the O-ring. Using SST, install the power steering oil pressure switch. SST: 09922-10010 without SST Torque: 21 N*m (210 kgf*cm, 15 ft.*lbf) with SST Torque: 15 N*m (148 kgf*cm, 11 ft.*lbf) TEXT IN ILLUSTRATION *1 Fulcrum Length HINT: Use a torque wrench with a fulcrum length of 30 cm (11.8 in.). When using a torque wrench with a fulcrum length that is not 30 cm (11.8 in.), calculate the torque specification for the torque wrench and SST based on the "without SST" torque specification. Refer to «PRECAUTION»(ref-524109-S11104823482013012800000) . Make sure SST and the torque wrench are connected in a straight line. Connect the power steering oil pressure switch connector.
2. INSTALL FAN AND GENERATOR V BELT Install the fan and generator V belt. Refer to «INSTALLATION»(ref-524246-S04919993912013012800000) .
3. ADD POWER STEERING FLUID
4. BLEED AIR FROM POWER STEERING SYSTEM . Refer to «ON-VEHICLE INSPECTION - Step 2»(ref-524279-S29238486632013012800000)
5. INSPECT FOR POWER STEERING FLUID LEAK
6. CHECK POWER STEERING FLUID LEVEL . Refer to «ON-VEHICLE INSPECTION - Step 3»(ref-524279-S29238486632013012800000)
7. INSTALL FRONT FENDER APRON SEAL RH . Refer to «INSTALLATION - Step 84»(ref-524246-S15625075792013012800000)
8. INSTALL FRONT WHEEL . Refer to «INSTALLATION - Step 8»(ref-524280-S16903400912013012800000)

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1. INSPECT CIRCUIT OPENING RELAY (C/OPN) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage is not applied to terminals 1 and 2 10 kohms or higher Battery voltage is applied to terminals 1 and 2 Below 1 ohms If the result is not as specified, replace the circuit opening relay.
2. INSPECT NO. 1 INTEGRATION RELAY (IG2) Check the IG2 fuse. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition IG2 fuse Always Below 1 ohms If the result is not as specified, replace the IG2 fuse. Check the IG2 relay. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1C-1 - 1A-4 Battery voltage not applied to terminals 1A-1 and 1A-3 10 kohms or higher Battery voltage applied to terminals 1A-1 and 1A-3 Below 1 ohms TEXT IN ILLUSTRATION *a Component without harness connected (Integration Relay) If the result is not as specified, replace the No. 1 integration relay.
3. INSPECT NO. 1 INTEGRATION RELAY (EFI) Check the EFI fuse. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition EFI fuse Always Below 1 ohms If the result is not as specified, replace the EFI fuse. Check the EFI relay. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1C-1 - 1B-4 Battery voltage not applied to terminals 1B-2 and 1B-3 10 kohms or higher Battery voltage applied to terminals 1B-2 and 1B-3 Below 1 ohms TEXT IN ILLUSTRATION *a Component without harness connected (Integration Relay) If the result is not as specified, replace the No. 1 integration relay.
4. INSPECT NO. 1 INTEGRATION RELAY (A/F) Check the A/F fuse. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/F fuse Always Below 1 ohms If the result is not as specified, replace the A/F fuse. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1C-1 - 1B-8 Battery voltage not applied to terminals 1B-4 and 1B-7 10 kohms or higher Battery voltage applied to terminals 1B-4 and 1B-7 Below 1 ohms TEXT IN ILLUSTRATION *a Component without harness connected (Integration Relay) If the result is not as specified, replace the No. 1 integration relay.
5. INSPECT AIR INJECTION VSV RELAY (AI-VSV) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage is not applied to terminals 1 and 2 10 kohms or higher Battery voltage is applied to terminals 1 and 2 Below 1 ohms If the result is not as specified, replace the air injection VSV relay.
6. INSPECT FUEL PUMP RELAY (FUEL PMP) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage is not applied to terminals 1 and 2 10 kohms or higher Battery voltage is applied to terminals 1 and 2 Below 1 ohms If the result is not as specified, replace the fuel pump relay.
7. INSPECT STARTER RELAY (ST) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage is not applied to terminals 1 and 2 10 kohms or higher Battery voltage is applied to terminals 1 and 2 Below 1 ohms If the result is not as specified, replace the starter relay.
8. INSPECT MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK) NOTE: The ACC relay and IG1 No. 1 relay are built into the main body ECU (driver side junction block). Inspect the ACC relay. Measure the resistance according to the value(s) in the table below. TEXT IN ILLUSTRATION *a Component without harness connected (Main Body ECU) - - Standard Resistance Tester Connection Condition Specified Condition 2D-17 - 2K-1 Battery voltage not applied to terminals 2A-48 and 2D-4 10 kohms or higher Battery voltage applied to terminals 2A-48 and 2D-4 Below 1 ohms If the result is not as specified, replace the main body ECU. Inspect the IG1 No. 1 relay. Measure the resistance according to the value(s) in the table below. TEXT IN ILLUSTRATION *a Component without harness connected (Main Body ECU) - - Standard Resistance Tester Connection Condition Specified Condition 2A-31 - 2K-1 Battery voltage not applied to terminals 2A-52 and 2D-4 10 kohms or higher Battery voltage applied to terminals 2A-52 and 2D-4 Below 1 ohms If the result is not as specified, replace the main body ECU.