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Steering Lock System (Diagnostic Codes & Circuit Tests): Overview Lexus GS III рестайлинг

Steering Column 14 illustrations ~1462 words

DESCRIPTION

If the steering lock ECU determines that there is a malfunction inside the ECU, it outputs this DTC. Diagnostic communication between the steering lock ECU and the Techstream is performed via the certification ECU as the steering lock ECU is not connected to the BEAN.

DTC No.DTC Detection ConditionTrouble Area
B2781When either condition below is met: Steering lock motor drive circuit is defective. Both lock and unlock position sensors detect "ON".Steering lock actuator (Steering lock ECU)

The power source control ECU controls the power supply to activate the steering lock motor. This prevents the steering from being locked while the vehicle is moving.

DTC No.DTC Detection ConditionTrouble Area
B2782Steering lock motor drive control circuit is defective.Wire harness Steering lock actuator (Steering lock ECU) Power source control ECU

Scheme 73

Scheme 73: WIRING DIAGRAM
Scheme 73: WIRING DIAGRAM

Scheme 74

Scheme 74: PROCEDURE
Scheme 74: PROCEDURE

Scheme 75

Scheme 75
Scheme 75

Scheme 76

Scheme 76
Scheme 76
  1. CHECK STEERING LOCK ACTUATOR Measure the voltage according to the value(s) in the table below. Standard voltage Tester Connection Condition Specified Condition K28-3 (IGE) - K28-2 (SGND) Power switch OFF Turn the power switch ON (ACC or IG) Motor active: Below 1 V Motor not active: 10 to 12 V K28-3 (IGE) - K28-2 (SGND) Adjust the shift lever to the P position Turn the power switch OFF Open the driver's door Motor active: Below 1 V Motor not active: 10 to 12 V HINT: The steering lock ECU is built into the steering lock actuator. These two parts are supplied as the steering column assembly. OK --> REPLACE STEERING COLUMN ASSEMBLY NG: Go to next step
  2. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - BODY GROUND) Disconnect the K28 connector from the steering lock actuator. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition K28-2 (SGND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  3. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - POWER SOURCE CONTROL ECU) Disconnect the K73 connector from the power source control ECU. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition K28-3 (IGE) - K73-32 (SLR+) Always Below 1 ohms K28-3 (IGE) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE POWER SOURCE CONTROL ECU

The steering lock ECU receives IG2 relay signals. Receiving the signals, the steering lock ECU determines that the vehicle is moving. The steering lock ECU does not lock the steering when it receives an IG2 relay ON signal (to prevent the steering from being locked while the vehicle is moving).

DTC No.DTC Detection ConditionTrouble Area
B2788Different information is obtained from IG2 signals received directly from the IG2 circuit, and from IG2 signals sent via LIN communication for a period of 1 second.IG2 relay Wire harness Power source control ECU Steering lock actuator (Steering lock ECU)

Scheme 77

Scheme 77: WIRING DIAGRAM
Scheme 77: WIRING DIAGRAM

Scheme 78

Scheme 78: PROCEDURE
Scheme 78: PROCEDURE

Scheme 79

Scheme 79
Scheme 79

Scheme 80

Scheme 80
Scheme 80
  1. INSPECT IGNITION RELAY NO. 2 Remove the IG2 relay from the engine room No. 1 relay block. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Specified Condition 3 - 5 10 kohms or higher 3 - 5 Below 1 ohms (when battery voltage is applied to terminals 1 and 2) NG --> REPLACE IGNITION RELAY NO. 2 OK: Go to next step
  2. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - BODY GROUND) Disconnect the K28 connector from the steering lock actuator. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition K28-1 (GND) - Body ground Always Below 1 ohms K28-2 (SGND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  3. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - BATTERY) Measure the voltage according to the value(s) in the table below. Standard voltage Tester Connection Condition Specified Condition K28-6 (IG2) - K28-1 (GND) Power switch ON (IG) 10 to 14 V K28-6 (IG2) - K28-2 (SGND) Power switch ON (IG) 10 to 14 V Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition *K28-6 (IG2) - K28-7 (B) Power switch OFF 10 kohms or higher HINT: *: This measurement is performed with the power switch OFF to check for a battery voltage short in the IG2 circuit. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE STEERING COLUMN ASSEMBLY

The steering lock ECU is connected to the power source control ECU and certification ECU. The steering lock ECU cannot activate the motor unless it obtains permission from both the ECUs.

Scheme 81

Scheme 81
Scheme 81
  1. CHECK VEHICLE CONDITION Check the condition of the steering lock system. Result Condition Proceed to Steering lock cannot be released A Steering cannot be locked B B --> See step 6 A: Go to next step
  2. READ VALUE USING TECHSTREAM (STEERING LOCK COMMAND) Connect the Techstream to the DLC3. Turn the power switch ON (IG). Turn the Techstream on. Enter the following menus: Body / Smart Access / Data List. SMART ACCESS Tester Display Measurement Item / Range Normal Condition Diagnostic Note Lock/Unlock Receive Steering lock command reception record/YES or NO YES: Steering lock/unlock signal received NO: Steering lock/unlock signal no received - Check if steering unlock command reception is confirmed. OK "YES" is displayed on the Techstream display. NG --> CHECK SMART ACCESS SYSTEM WITH PUSH-BUTTON START OK: Go to next step
  3. CHECK STEERING LOCK ACTUATOR Measure the voltage according to the value(s) in the table below. STANDARD VOLTAGE Tester Connection Condition Specified Condition K28-3 (IGE) - K28-2 (SGND) Power switch OFF Turn the power switch ON (ACC or IG) Motor active: Below 1 V Motor not active: 10 to 12 V OK --> PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE NG: Go to next step
  4. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - BODY GROUND) See step 2 NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  5. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - POWER SOURCE CONTROL ECU) Disconnect the K73 connector from the power source control ECU. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition K28-3 (IGE) - K73-32 (SLR+) Always Below 1 ohms K28-3 (IGE) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE POWER SOURCE CONTROL ECU
  6. CHECK STEERING LOCK ACTUATOR Measure the voltage according to the value(s) in the table below. Standard voltage Tester Connection Condition Specified Condition K28-3 (IGE) - K28-2 (SGND) Adjust the shift lever to the P position Turn the power switch OFF Open the driver's door Motor active: Below 1 V Motor not active: 10 to 12 V OK --> PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE NG: Go to next step
  7. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - POWER SOURCE CONTROL ECU) Disconnect the K28 connector from the steering lock actuator. Disconnect the K73 connector from the power source control ECU. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition K28-3 (IGE) - K73-32 (SLR+) Always Below 1 ohms K28-3 (IGE) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE POWER SOURCE CONTROL ECU

The unlock position sensor is one of the components comprising the steering lock actuator. The sensor switch contact closes when the steering lock is released. The steering lock release signal is then sent to the power source control ECU, which permits engine start. This prevents the engine from being started with the steering locked.

Scheme 82

Scheme 82: WIRING DIAGRAM
Scheme 82: WIRING DIAGRAM

Scheme 83

Scheme 83: PROCEDURE
Scheme 83: PROCEDURE

Scheme 84

Scheme 84
Scheme 84
  1. CHECK STEERING LOCK ACTUATOR ASSEMBLY Measure the voltage according to the value(s) in the table below. Standard voltage Tester Connection Condition Specified Condition K28-4 (SLP1) - K28-2 (SGND) Power switch OFF Turn the power switch ON (ACC or IG) Below 1 V OK --> CHECK PUSH BUTTON START FUNCTION NG: Go to next step
  2. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - POWER SOURCE CONTROL ECU) Disconnect the K28 connector from the steering lock actuator. Disconnect the K73 connector from the power source control ECU. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition K28-4 (SLP1) - K73-26 (SLP) Always Below 1 ohms K28-4 (SLP1) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE STEERING COLUMN ASSEMBLY

This circuit supplies power source voltage from the battery to terminal B of the steering lock ECU. This is used as power source for the CPU, motor, communication, and peripheral circuits.

Scheme 85

Scheme 85: WIRING DIAGRAM
Scheme 85: WIRING DIAGRAM

Scheme 86

Scheme 86: PROCEDURE
Scheme 86: PROCEDURE
  1. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - BODY GROUND) See step 2 NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  2. CHECK WIRE HARNESS (STEERING LOCK ACTUATOR - BATTERY) Measure the voltage according to the value(s) in the table below. Standard voltage Tester Connection Condition Specified Condition K28-7 (B) - K28-1 (GND) Always 10 to 14 V K28-7 (B) - K28-2 (SGND) Always 10 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (STEERING LOCK ACTUATOR - BATTERY) OK --> PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

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