VARIABLE GEAR RATIO STEERING SYSTEM, Diagnostic DTC:C15A5

DTC Code DTC Name
C15A5 Lock Mechanism Circuit

DESCRIPTION

If the VGRS ECU (front steering control ECU) detects a malfunction in the lock mechanism, it turns the master warning light on, and stores DTC C15A5.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Return-to-normal Condition
C15A5 Lock Mechanism Circuit

All conditions are met:


  • The power switch is on (IG).

  • A short in the motor circuit or an internal malfunction in the ECU is detected for approximately 0.6 seconds or more.

  • Steering actuator assembly

  • VGRS ECU (front steering control ECU)

  • Harness or connector

 Comes on Power switch on (IG) again
DTC Detection Conditions:
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition Power switch is on (IG) ○ ○
Malfunction Status A short in the motor circuit ○ -
An internal ECU malfunction - ○
Detection Time Approximately 0.6 seconds or more Approximately 0.6 seconds or more
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

Refer to DTC C15A3.

Click here

CAUTION / NOTICE / HINT

Note

When replacing the VGRS ECU (front steering control ECU) or steering actuator assembly, perform actuator angle neutral point calibration and initialization after replacing parts.

Click here

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (LV, LG TERMINAL)


    1. B004R1SC68
      *a

      Component with harness connected

      (VGRS ECU [Front Steering Control ECU])

      Turn the power switch on (IG).

    2. Measure the voltage according to the value(s) in the table below.

      Tech Tips

      With the connector connected to the VGRS ECU (front steering control ECU), measure the voltage from the rear of the connector.

      Standard Voltage
      Tester Connection Condition Specified Condition
      G78-2 (LV) - Body ground Power switch on (IG) 11 to 14 V
      G78-6 (LG) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT STEERING ACTUATOR ASSEMBLY Click here

    OK

  2. READ VALUE USING GTS (LOCK SOLENOID VOLTAGE)


    1. Turn the power switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (READY).

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / VGRS / Data List.


      Chassis > VGRS > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Lock Solenoid Voltage Lock solenoid voltage

      Min.: 0.00 V

      Max.: 255.99 V

      		 0 to 14 V -

      Chassis > VGRS > Data List
      Tester Display
      Lock Solenoid Voltage
      OK
      0 to 14 V (power switch on [READY])
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) Click here

  3. INSPECT STEERING ACTUATOR ASSEMBLY


    1. Turn the power switch off.

    2. Disconnect the G78 VGRS ECU (front steering control ECU) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Tech Tips

      Measure the resistance of the steering actuator assembly at the connector of the VGRS ECU (front steering control ECU).

      Standard Resistance
      Tester Connection Condition Specified Condition
      G78-2 (LV) - G78-6 (LG) Always 10 to 30 Ω
      G78-2 (LV) - Body ground Always 100 kΩ or higher
      G78-6 (LG) - Body ground Always 100 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) Click here

    NG

  4. CHECK HARNESS AND CONNECTOR (VGRS ECU (FRONT STEERING CONTROL ECU) - STEERING ACTUATOR ASSEMBLY)


    1. Turn the power switch off.

    2. Disconnect the G78 VGRS ECU (front steering control ECU) connector.

    3. Disconnect the G33 steering actuator assembly connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G78-2 (LV) - G33-7 (LV+) Always Below 1 Ω
      G78-6 (LG) - G33-16 (LG+) Always Below 1 Ω
      G78-2 (LV) - G78-6 (LG) Always 10 to 30 Ω
      G78-2 (LV) or G33-7 (LV+) - Body ground Always 100 kΩ or higher
      G78-6 (LG) or G33-16 (LG+) - Body ground Always 100 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE STEERING ACTUATOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR