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Variable Gear Ratio Steering (Diagnostic Codes & Symptom Tests): Diagnosis Lexus LX J200

Electronic Steering 8 illustrations ~1554 words

INSPECTION PROCEDURE

HINT

When DTC C15A2/62 is output, a short circuit inside the steering actuator or inside the steering control ECU is suspected.

Scheme 33

Scheme 33: PROCEDURE
Scheme 33: PROCEDURE

Scheme 34

Scheme 34
Scheme 34
  1. CHECK HARNESS AND CONNECTOR (STEERING CONTROL ECU - STEERING ACTUATOR) Disconnect the E83 steering control ECU connector. Disconnect the E85 steering actuator connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E83-1 (BMV) - E83-2 (BMU) Always 10 kohms or higher E83-1 (BMV) - E83-3 (BMW) E83-2 (BMU) - E83-3 (BMW) E83-1 (BMV) - E85-5 (BMV+) Always Below 1 ohms E83-2 (BMU) - E85-4 (BMU+) E83-3 (BMW) - E85-13 (BMW+) E83-1 (BMV) - Body ground Always 10 kohms or higher E83-2 (BMU) - Body ground E83-3 (BMW) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  2. CHECK STEERING ACTUATOR Disconnect the E83 steering control ECU connector. Measure the resistance according to the value(s) in the table below. HINT: The resistance must be measured with the steering actuator connector connected. Standard Resistance Tester Connection Condition Specified Condition E83-1 (BMV) - E83-2 (BMU) Always Below 1 ohms E83-1 (BMV) - E83-3 (BMW) E83-2 (BMU) - E83-3 (BMW) E83-1 (BMV) - Body ground Always 10 kohms or higher E83-2 (BMU) - Body ground E83-3 (BMW) - Body ground NG --> See step 3 OK --> See step 4
  3. REPLACE STEERING ACTUATOR ASSEMBLY. Refer to «REMOVAL»(ref-385254-S28279630502011021400000)
  4. REPLACE STEERING CONTROL ECU. Refer to «REMOVAL»(ref-385254-S25865253242011021400000)

HINT

Only the actuator can be checked in this procedure. If it is normal, the steering control ECU is faulty.

Scheme 35

Scheme 35: PROCEDURE
Scheme 35: PROCEDURE

Scheme 36

Scheme 36
Scheme 36

Scheme 37

Scheme 37
Scheme 37
  1. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E82-7 (PGND) - Body ground Always Below 1 ohms E83-8 (PGD2) - Body ground Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition E82-8 (PIG) - Body ground Always 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  2. CHECK HARNESS AND CONNECTOR (STEERING CONTROL ECU - STEERING ACTUATOR) Disconnect the E83 steering control ECU connector. Disconnect the E85 steering actuator connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E83-1 (BMV) - E83-2 (BMU) Always 10 kohms or higher E83-1 (BMV) - E83-3 (BMW) E83-2 (BMU) - E83-3 (BMW) E83-1 (BMV) - E85-5 (BMV+) Always Below 1 ohms E83-2 (BMU) - E85-4 (BMU+) E83-3 (BMW) - E85-13 (BMW+) E83-1 (BMV) - Body ground Always 10 kohms or higher E83-2 (BMU) - Body ground E83-3 (BMW) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  3. CHECK STEERING ACTUATOR Disconnect the E83 steering control ECU connector. Measure the resistance according to the value(s) in the table below. HINT: The resistance must be measured with the steering actuator connector connected. Standard Resistance Tester Connection Condition Specified Condition E83-1 (BMV) - E83-2 (BMU) Always Below 1 ohms E83-1 (BMV) - E83-3 (BMW) E83-2 (BMU) - E83-3 (BMW) E83-1 (BMV) - Body ground Always 10 kohms or higher E83-2 (BMU) - Body ground E83-3 (BMW) - Body ground NG --> See step 6 OK: Go to next step
  4. CHECK DTC Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-385244-S06342001682011021400000) . RESULT Result Proceed to C15A1/61 is output A C15A1/61 is not output B B --> See step 5 A --> See step 6
  5. REPLACE STEERING CONTROL ECU. Refer to «REMOVAL»(ref-385254-S25865253242011021400000)
  6. REPLACE STEERING ACTUATOR ASSEMBLY. Refer to «REMOVAL»(ref-385254-S28279630502011021400000)

HINT

The fault may be intermittent. Check the harnesses and connectors thoroughly and retest.

Scheme 38

Scheme 38: PROCEDURE
Scheme 38: PROCEDURE
  1. CHECK STEERING CONTROL ECU (POWER SOURCE CIRCUIT) Record and clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-385244-S06342001682011021400000) . Measure the resistance and voltage according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E82-7 (PGND) - Body ground Always Below 1 ohms E83-8 (PGD2) - Body ground Standard Voltage Tester Connection Switch Condition Specified Condition E82-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  2. RECONFIRM DTC OUTPUT Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-385244-S06342001682011021400000) . RESULT Result Proceed to C15C6/77 is not output A C15C6/77 is output B B --> See step 4 A --> See step 3
  3. USE SIMULATION METHOD TO CHECK. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-385196-S09917434812011021400000)
  4. REPLACE STEERING CONTROL ECU. Refer to «REMOVAL»(ref-385254-S25865253242011021400000)

HINT

The fault may be intermittent. Check the harnesses and connectors thoroughly and retest.

Scheme 39

Scheme 39: PROCEDURE
Scheme 39: PROCEDURE
  1. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) Record and clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-385244-S06342001682011021400000) . Measure the resistance and voltage according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E82-7 (PGND) - Body ground Always Below 1 ohms E83-8 (PGD2) - Body ground Standard Voltage Tester Connection Condition Specified Condition E82-8 (PIG) - Body ground Always 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  2. RECONFIRM DTC OUTPUT Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-385244-S06342001682011021400000) . RESULT Result Proceed to C15C7/78 or C15C8/79 is not output A C15C7/78 or C15C8/79 is output B B --> See step 4 A --> See step 3
  3. USE SIMULATION METHOD TO CHECK. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-385196-S09917434812011021400000)
  4. REPLACE STEERING CONTROL ECU. Refer to «REMOVAL»(ref-385254-S25865253242011021400000)

This problem may be caused by a malfunction in the vehicle stability control system or steering system.

Make sure that no DTC is output for the skid control ECU or steering control ECU before proceeding with the following procedures.

If a DTC is output for either of these ECUs, first troubleshoot it and then proceed to the troubleshooting below.

HINT

This problem may be caused by a malfunction in the vehicle stability control system or steering system.

Make sure that no DTC is output for the skid control ECU or steering control ECU before proceeding with the following procedures.

If a DTC is output for either of these ECUs, first troubleshoot it and then proceed to the troubleshooting below.

Scheme 40

Scheme 40: PROCEDURE
Scheme 40: PROCEDURE
  1. READ VALUE USING TECHSTREAM (RECORD OF OVERHEAT) Use the Data List to check if the record of overheat is functioning properly. VGRS Tester Display Measurement Item/Range Normal Condition Diagnostic Note Motor Overheat Record Record of continuous overheat preventive control/Rec or Unrec Rec or Unrec - RESULT Result Proceed to "Rec" (Record of motor overheating) A "Unrec" (No record of motor overheating) B HINT: If "Rec" is displayed, reset the setting to "Unrec". Enter the VGRS menu on the Techstream, select record clearance, and follow the prompts to set to "Unrec". B --> See step 3 A: Go to next step
  2. CHECK HEAT PROTECTION FUNCTION FOR STEERING ACTUATOR Turn the engine switch on (IG) and wait for 30 minutes until the steering actuator cools down. Start the engine and slowly turn the steering wheel from lock to lock (approximately 90°/sec.) 3 times. HINT: If turning the steering wheel quickly while driving at low speeds, the steering angle may differ between the left and right, or the steering wheel may become off-center. However, this is not a malfunction. Check the number of turns from lock to lock. RESULT Result Proceed to 3.2 turns A 2.7 turns B B --> VGRS SYSTEM IS NORMAL A: Go to next step
  3. CHECK STEERING EFFORT Start the engine. Turn the steering wheel. Measure the steering effort. Standard steering effort Below 6.9 N*m (70 kgf*cm, 61 in.*lbf) HINT: After completing the inspection or repair, attempt to simulate the problem and then perform "Read Value Using Techstream" above again to reconfirm that the problem does not occur. NG --> See step 6 OK: Go to next step
  4. CHECK STEERING ACTUATOR Check for abnormal noise or vibration in the steering actuator. OK Neither abnormal noise nor vibration occurs. NG --> See step 7 OK: Go to next step
  5. CHECK STEERING CONTROL ECU (POWER SOURCE CIRCUIT) Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E82-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V E82-8 (PIG) - Body ground Always Turn the engine switch off. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E82-7 (PGND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 8
  6. GO TO POWER STEERING SYSTEM (PROBLEM SYMPTOMS TABLE). Refer to «PROBLEM SYMPTOMS TABLE»(ref-385176-S37199500682011021400000)
  7. GO TO STEERING WHEEL VIBRATES OR ABNORMAL NOISE IS HEARD FROM STEERING WHEEL. Refer to «Steering Wheel Vibrates or Abnormal Noise is Heard from Steering Wheel»(ref-385253-S25846856182011021400000)
  8. REPLACE STEERING CONTROL ECU. Refer to «REMOVAL»(ref-385254-S25865253242011021400000)

HINT

  1. Check that the steering wheel is centered.
  2. After checking that no DTC is output for the VGRS system, perform the following procedure.

HINT

Check that no DTC is output for the VGRS system and vehicle stability control system.

HINT

Check that there is no problem in CAN communication before performing the following procedure.

If there are any problems in CAN communication, first troubleshoot them and then proceed to the troubleshooting below.

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