VARIABLE GEAR RATIO STEERING SYSTEM, Diagnostic DTC:C15C7/78, C15C8/79

DTC Code DTC Name
C15C7/78 DC Motor Power Source Voltage
C15C8/79 Power Supply Relay Failure

DESCRIPTION

The VGRS ECU (front steering control ECU) monitors terminal PIG (motor power source voltage) in order to detect malfunctions in the power supply relay (located inside the VGRS ECU (front steering control ECU)).

If the VGRS ECU (front steering control ECU) detects a malfunction, it turns the master warning light on, and stores these DTCs.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Return-to-normal Condition
C15C7/78 DC Motor Power Source Voltage

Both conditions are met for approximately 2.4 seconds or more:


  • The engine switch is on (IG).

  • When the PIG voltage is 18.5 V or higher or 7 V or less, an open or short in the PIG circuit, or an internal malfunction in the ECU is detected.

  • VGRS fuse

  • Battery

  • Charging system

  • VGRS ECU (front steering control ECU)

  • Harness or connector

 Comes on Engine switch on (IG) again
C15C8/79 Power Supply Relay Failure

All conditions are met for approximately 1.5 seconds or more:


  • The engine switch is on (IG).

  • Control has not started.

  • An open / short in the PIG circuit or an internal malfunction in the ECU is detected.

  • VGRS fuse

  • Battery

  • Charging system

  • VGRS ECU (front steering control ECU)

  • Harness or connector

 Comes on Engine switch on (IG) again

WIRING DIAGRAM

B003TRZE02
*a from Battery
*b VGRS ECU (Front Steering Control ECU)

CAUTION / NOTICE / HINT

Note


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

    Click here

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. READ VALUE USING GTS (PIG POWER SUPPLY VOLTAGE)


    1. Turn the engine switch off.

    2. Connect the GTS to the DLC3.

    3. Start the engine.

    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
      PIG Power Supply Voltage PIG power supply voltage

      Min.: 0.00 V

      Max.: 255.99 V

      		 11 to 14 V -

      Chassis > VGRS > Data List
      Tester Display
      PIG Power Supply Voltage
      OK
      11 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  2. INSPECT VGRS ECU (FRONT STEERING CONTROL ECU) (PIG, PGND TERMINAL)


    1. Turn the engine switch off.

    2. Check the connection of the VGRS ECU (front steering control ECU) connector and the condition of the terminals.

    3. B003U48C02
      *a

      Component without harness connected

      (VGRS ECU [Front Steering Control ECU])

      Disconnect the A60 VGRS ECU (front steering control ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (PIG) - 1 (PGND) Always 100 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) - LHD REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) Click here
    REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) - RHD REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (PGND, PGD2 TERMINAL)


    1. Turn the engine switch off.

    2. B003X2XC05
      *a

      Front view of wire harness connector

      (to VGRS ECU [Front Steering Control ECU])

      Disconnect the K17 and A60 VGRS ECU (front steering control ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A60-1 (PGND) - Body ground Always Below 1 Ω
      K17-13 (PGD2) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (PIG, PGND TERMINAL)


    1. Turn the engine switch off.

    2. B003VFQC05
      *a

      Front view of wire harness connector

      (to VGRS ECU [Front Steering Control ECU])

      Disconnect the A60 VGRS ECU (front steering control ECU) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A60-2 (PIG) - A60-1 (PGND) Always 11 to 14 V
      Result
      Result Proceed to
      The voltage is in the range of 11 to 14 V A
      The voltage is below 11 V B
      The voltage is higher than 14 V C

    A

    REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) - LHD REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) Click here
    REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) - RHD REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) Click here

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    C

    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Click here