ELECTRONIC SHIFT LEVER SYSTEM(for 8GR-FKS), Diagnostic DTC:P176A87

DTC Code DTC Name
P176A87 Lost Communication with Fail Safe Signal (Gear Shift Control Module "A") Missing Message

DESCRIPTION

The shift control ECU sends SBFS (fail-safe) signals to the ECM.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate
P176A87 Lost Communication with Fail Safe Signal (Gear Shift Control Module "A") Missing Message

The SBFS (fail-safe) signals sent from the shift control ECU cannot be received by the ECM continuously for 2 seconds or more.

(1 trip detection logic)

  • Shift control ECU

  • ECM

  • Wire harness or connector

 Does not come on

  • Master Warning Light


    • Comes on

  • Multi-information Display Error Message


    • Displayed

CONFIRMATION DRIVING PATTERN

Tech Tips

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the All Readiness check procedure.

Click here


  1. Start the engine and wait for 2 minutes or more.

WIRING DIAGRAM

B006DY9E05
*a SBFS
*b Shift Control ECU

CAUTION / NOTICE / HINT

Note

The vehicle is equipped with a sub-battery. Therefore, ensure there is no power being supplied to the vehicle when disconnecting or reconnecting the connector of the shift control ECU and when removing or installing the shift control ECU.

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PROCEDURE


  1. CHECK SHIFT CONTROL ECU (CHECK SBFS TERMINAL WAVEFORM)


    1. B006H00C03
      *a

      Front view of wire harness connector

      (to ECM)
      *b Waveform (Fail-safe signal)

      Disconnect the ECM connector.

    2. Connect an oscilloscope between the ECM connector terminal specified in the table below and body ground.

    3. Turn the engine switch on (IG) and measure the waveform.

      Tester Connection Condition Equipment Setting
      A56-56 (SBFS) - Body ground Engine switch on (IG) 10 V/DIV., 20 ms./DIV.

      Note

      Turning the engine switch on (IG) with the connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

      Tech Tips

      The waveforms differ when the shift control ECU is malfunctioning.

    4. Turn the engine switch off.

    5. Reconnect the ECM connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (SHIFT CONTROL ECU - ECM)


    1. Disconnect the G81 shift control ECU connector.

    2. Disconnect the A56 ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      G81-3 (SBFS) - A56-56 (SBFS) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      G81-3 (SBFS) or A56-56 (SBFS) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the A56 ECM connector.

    5. Reconnect the G81 shift control ECU connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SHIFT CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR