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Automatic Transaxle - Diagnosis: Overview Lexus ES XV30 facelift

Automatic Trans 9 illustrations ~1512 words

SYSTEM DESCRIPTION

The ECM uses the signals from the throttle position sensor, Air-flow meter and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.

Then the ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect a mechanical trouble of the shift solenoid valve DSL, valve body and torque converter clutch.

DTC No.DTC Detection ConditionTrouble Area
P0741Lock-up does not occur when driving in lock-up range (normal driving at 80 km/h [50 mph]), or lock-up remains ON in lockup OFF range (2 trip detection logic)Shift solenoid valve DSL is stuck open or closed Valve body blocked or stuck Shift solenoid valve DSL Lock-up clutch

DTC P0741

Scheme 106

Scheme 106: INSPECTION PROCEDURE
Scheme 106: INSPECTION PROCEDURE

Scheme 107

Scheme 107
Scheme 107

Scheme 108

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Scheme 108

Scheme 109

Scheme 109
Scheme 109
  1. PERFORM ACTIVE TEST BY OBD II SCAN TOOL OR HAND-HELD TESTER Warm up the engine. Turn the ignition switch OFF. Connect the OBD II scan tool or Hand-held tester to the DLC3. Turn the ignition switch ON and push the OBD II scan tool or Hand-held tester main SW ON. Select the item "LOCK UP" in the ACTIVE TEST and operate the Lock-up solenoid valves on the OBD II scan tool or Hand-held tester. NOTE: The values given below for "Normal Condition" are representative values, so a vehicle may still be normal even if its value differs from those listed here. Do not depend solely on the "Normal Condition" here when deciding whether or not the part is faulty. LOCK UP TEST DETAILS Item Test Details Diagnostic Note LOCK UP [Test Details] Control the shift solenoid DSL to set the ATM to the lock-up condition. [Vehicle Condition] Vehicle Speed: 58 km/h (36 mph) or more Possible to check the DSL operation. OK: CHECK AND REPLACE ECM (See «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-210284-S34294141912005122000000) ) NG: Go to next step.
  2. INSPECT TRANSMISSION WIRE (DSL) Disconnect the transmission wire connector (E1) from the transaxle. Measure resistance between the terminal DSL and body ground. OK: Resistance: 11 - 13 ohm at 20 °C (68 °F) NG : Go to step 4 . OK : Go to next step.
  3. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM) Connect the transmission wire connector. Disconnect the ECM connector. Measure the resistance between terminals DSL and E1. OK: Resistance: 11 - 13 ohm at 20 °C (68 °F) NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-210284-S34294141912005122000000) ) OK: Go to next step.
  4. INSPECT SHIFT SOLENOID VALVE DSL Remove the shift solenoid valve DSL. Applying 490 kPa (5 kgf/cm 2 , 71 psi) of compressed air, check that the solenoid valve does not leak the air. OK: Solenoid valve does not leak air. When battery voltage is supplied to the shift solenoid valve, check that the valve opens. OK: Solenoid valve opens. Measure the resistance between the terminal DSL of shift solenoid valve and the solenoid body. OK: Resistance: 11 - 13 ohm at 20 °C (68 °F) Connect positive (+) lead to the terminal of solenoid connector, negative (-) lead to the solenoid body. OK: The solenoid valve makes an operating noise. NG : REPLACE SHIFT SOLENOID VALVE DSL OK : Go to next step.
  5. CHECK TRANSMISSION WIRE (See «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-210284-S34294141912005122000000) ) NG: REPAIR OR REPLACE TRANSMISSION WIRE (See «REPLACEMENT»(/lexus/es/xv30-facelift-2003-2006/remont/automatic-trans/#automatic-transaxle-on-vehcle-service) ) OK: Go to next step.
  6. INSPECT TRANSMISSION VALVE BODY ASSY NG : REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSY (See «REPLACEMENT»(/lexus/es/xv30-facelift-2003-2006/remont/automatic-trans/#automatic-transaxle-on-vehcle-service) ) OK : Go to next step.
  7. INSPECT TORQUE CONVERTER CLUTCH ASSY (See «INSPECTION»(/lexus/es/xv30-facelift-2003-2006/remont/automatic-trans/#automatic-transaxle-on-vehcle-service) ) NG : REPLACE TORQUE CONVERTER CLUTCH ASSY OK : REPAIR AUTOMATIC TRANSAXLE ASSY (See «REPLACEMENT»(/lexus/es/xv30-facelift-2003-2006/remont/automatic-trans/#automatic-transaxle-on-vehcle-service) )

The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).

Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical troubles of the shift solenoid valves and valve body.

DTC No.DTC Detecting ConditionTrouble Area
P0746The gear required by the ECM does not match the actual gear when driving (2-trip detection logic)Shift solenoid valve SL1 is stuck open or closed Valve body is blocked up or stuck Automatic transaxle (clutch, brake or gear etc.)
P0766Shift solenoid valve S4 is stuck open or closed Valve body is blocked up or stuck Automatic transaxle (clutch, brake or gear etc.)
P0771Shift solenoid valve SR is stuck open or closed Valve body is blocked up or stuck Automatic transaxle (clutch, brake or gear etc.)
P0776Shift solenoid valve SL2 is stuck open or closed Valve body is blocked up or stuck Automatic transaxle (clutch, brake or gear etc.)
P0796Shift solenoid valve SL3 is stuck open or closed Valve body is blocked up or stuck Automatic transaxle (clutch, brake or gear etc.)

DTC P0746, P0766, P0771, P0776 AND P0796

HINT

  1. Start the inspection from step 1 when DTC P0746 is output.
  2. Start the inspection from step 1 when DTC P0776 is output.
  3. Start the inspection from step 1 when DTC P0796 is output.
  4. Start the inspection from step 2 when DTC P0766 is output.
  5. Start the inspection from step 2 when DTC P0771 is output.

Scheme 110

Scheme 110: INSPECTION PROCEDURE
Scheme 110: INSPECTION PROCEDURE

Scheme 111

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Scheme 112

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Scheme 113

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Scheme 114
  1. PERFORM ACTIVE TEST BY OBD II SCAN TOOL OR HAND-HELD TESTER Warm up the engine. Turn the ignition switch OFF. Connect the OBD II scan tool or Hand-held tester to the DLC3. Turn the ignition switch ON and push the OBD II scan tool or Hand-held tester main SW ON. Select the item "SHIFT" in the ACTIVE TEST and operate the shift solenoid valves on the OBD II scan tool or Hand-held tester. NOTE: The values given below for "Normal Condition" are representative values, so a vehicle may still be normal even if its value differs from those listed here. Do not depend solely on the "Normal Condition" here when deciding whether or not the part is faulty. SHIFT - TEST DETAILS Item Test Details Diagnostic Note SHIFT [Test Details] Operate the shift solenoid valve and set the each shift position by yourself. [Vehicle Condition] Less than 50 km/h (31 mph) [Others] Press --> button: Shift up Press <-- button: Shift down Possible to check the operation of the shift solenoid values. SHIFT TEST RESULT A NG (SL1) B NG (SL2) C NG (SL3) NG(A): Go to step 3. NG(B): Go to step 4. NG(C): Go to step 5. OK: CHECK AND REPLACE ECM (See «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-210284-S34294141912005122000000) )
  2. PERFORM ACTIVE TEST BY OBD II SCAN TOOL OR HAND-HELD TESTER Warm up the engine. Turn the ignition switch OFF. Connect the OBD II scan tool or Hand-held tester to the DLC3. Turn the ignition switch ON and push the OBD II scan tool or Hand-held tester main SW ON. Select the item "SHIFT" in the ACTIVE TEST and operate the shift solenoid valves on the OBD II scan tool or Hand-held tester. NOTE: The values given below for "Normal Condition" are representative values, so a vehicle may still be normal even if its value differs from those listed here. Do not depend solely on the "Normal Condition" here when deciding whether or not the part is faulty. SHIFT TEST DETAILS Item Test Details Diagnostic Note SHIFT [Test Details] Operate the shift solenoid valve and set the each shift position by yourself. [Vehicle Condition] Less than 50 km/h (31 mph) [Others] Press --> button: Shift up Press <-- button: Shift down Possible to check the operation of the shift solenoid values. SHIFT TEST RESULT A NG (S4) B NG (SR) NG(A): Go to step 6. NG(B): Go to step 7. OK: CHECK AND REPLACE ECM (See «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-210284-S34294141912005122000000) )
  3. INSPECT SHIFT SOLENOID VALVE (SL1) Remove the shift solenoid valve SL1. Measure the resistance between terminals. OK: Resistance: 5.0 - 5.6 ohm at 20°C (68°F) Connect the positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector, then check the movement of the valve. OK: The solenoid makes an operating noise. OK : Go to step 8 . NG : REPLACE SHIFT SOLENOID VALVE (SL1)
  4. INSPECT SHIFT SOLENOID VALVE (SL2) Remove the shift solenoid valve SL2. Measure the resistance between terminals. OK: Resistance: 5.0 - 5.6 ohm at 20°C (68°F) Connect the positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector, then check the movement of the valve. OK: The solenoid makes an operating noise. OK : Go to step 8 . NG : REPLACE SHIFT SOLENOID VALVE(SL2)
  5. INSPECT SHIFT SOLENOID VALVE (SL3) Remove the shift solenoid valve SL3. Measure the resistance between terminals. OK: Resistance: 5.0 - 5.6 ohm at 20°C (68°F) Connect the positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector, then check the movement of the valve. OK: The solenoid makes an operating noise. OK : Go to step 8 . NG : REPLACE SHIFT SOLENOID VALVE (SL3)
  6. INSPECT SHIFT SOLENOID VALVE (S4) Remove the shift solenoid valve S4. Measure the resistance between the solenoid connector and the solenoid body. OK: Resistance: 11 - 15 ohm at 20 °C (68 °F) Connector positive (+) lead to the terminal of solenoid connector, negative (-) lead to the solenoid body. OK: The solenoid makes an operating noise. OK : Go to step 8 . NG : REPLACE SHIFT SOLENOID VALVE (S4)
  7. INSPECT SHIFT SOLENOID VALVE (SR) Remove the shift solenoid valve SR. Measure the resistance between the solenoid connector and the solenoid body. OK: Resistance: 11 - 15 ohm at 20°C (68°F) Connector positive (+) lead to the terminal of solenoid connector, negative (-) lead to the solenoid body. OK: The solenoid makes an operating noise. OK : Go to step 8. NG : REPLACE SHIFT SOLENOID VALVE (SR)
  8. INSPECT TRANSMISSION VALVE BODY ASSY NG : REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSY (See «REPLACEMENT»(/lexus/es/xv30-facelift-2003-2006/remont/automatic-trans/#automatic-transaxle-on-vehcle-service) ) OK : Go to next step.
  9. INSPECT TORQUE CONVERTER CLUTCH ASSY (See «INSPECTION»(/lexus/es/xv30-facelift-2003-2006/remont/automatic-trans/#automatic-transaxle-on-vehcle-service) ) NG : REPLACE TORQUE CONVERTER CLUTCH ASSY OK : REPAIR AUTOMATIC TRANSAXLE ASSY (See «REPLACEMENT»(/lexus/es/xv30-facelift-2003-2006/remont/automatic-trans/#automatic-transaxle-on-vehcle-service) )

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