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 (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 (steering control ECU)).

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

DTC No. DTC Detection Condition Trouble Area
C15C7/78

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 (steering control ECU)

  • Harness or connector
C15C8/79

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 (steering control ECU)

  • Harness or connector

WIRING DIAGRAM

B0018JZE09
*a from Battery
*b VGRS ECU (Steering Control ECU)

CAUTION / NOTICE / HINT

Note


  • When replacing the VGRS ECU (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.

      VGRS
      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 -

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

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


    1. Turn the engine switch off.

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

    3. B0019BME02
      Text in Illustration
      *a

      Component without harness connected

      (VGRS ECU [Steering Control ECU])

      Disconnect the E127 VGRS ECU (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
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE VGRS ECU (STEERING CONTROL ECU) Click here

    C

    REPLACE VGRS ECU (STEERING CONTROL ECU) Click here

    A

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


    1. Turn the engine switch off.

    2. B0019BIE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to VGRS ECU [Steering Control ECU])

      Disconnect the VGRS ECU (steering control ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E127-1 (PGND) - Body ground Always Below 1 Ω
      E129-13 (PGD2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Turn the engine switch off.

    2. B001APQE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to VGRS ECU [Steering Control ECU])

      Disconnect the VGRS ECU (steering control ECU) connector.

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

      Tech Tips

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E127-2 (PIG) - E127-1 (PGND) Always 11 to 14 V
      Result
      Result Proceed to
      The voltage is in the range of 11 to 14 V (for LHD) A
      The voltage is in the range of 11 to 14 V (for RHD) B
      The voltage is below 11 V C
      The voltage is higher than 14 V D

    A

    REPLACE VGRS ECU (STEERING CONTROL ECU) Click here

    B

    REPLACE VGRS ECU (STEERING CONTROL ECU) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    D

    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY