VARIABLE GEAR RATIO STEERING SYSTEM, Diagnostic DTC:C15C7/78, C15C8/72

DTC Code DTC Name
C15C7/78 DC Motor Power Source Voltage
C15C8/72 DC Motor Power Source Voltage(ECU Start-up)

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 on the master warning light, stores these DTCs and stops VGRS operation.

DTC Code 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 (front 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 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

WIRING DIAGRAM

A01FEO9E01

INSPECTION PROCEDURE

Note


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

  • Since DTC C1B09/19 is stored in the DRS ECU (rear steering control ECU), after performing repairs on the VGRS system, clear the DTCs for the dynamic rear steering system.

  • 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
      11 to 14 V

    NG

    INSPECT FRONT STEERING CONTROL ECU (PIG, PGND TERMINAL) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  2. INSPECT 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. A01FI6OE01
      Text in Illustration
      *a

      Component without harness connected

      (VGRS ECU [Front Steering Control ECU])

      Disconnect the A31 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

    NG

    REPLACE FRONT STEERING CONTROL ECU Click here

    OK

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


    1. Turn the engine switch off.

    2. A01FDLWE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to VGRS ECU [Front Steering Control ECU])

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

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A31-1 (PGND) - Body ground Engine switch off Below 1 Ω
      N104 (PGD2) - Body ground Engine switch off 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. A01FGZHE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to VGRS ECU [Front Steering Control ECU])

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

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A31-2 (PIG) - A31-1 (PGND) Engine switch off 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

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    C

    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Click here

    A

    REPLACE FRONT STEERING CONTROL ECU Click here