AIR SUSPENSION SYSTEM, Diagnostic DTC:C176712, C176A12, C176D12, C177012

DTC Code DTC Name
C176712 No.1 Solenoid Circuit Circuit Short to Battery
C176A12 No.2 Solenoid Circuit Circuit Short to Battery
C176D12 No.3 Solenoid Circuit Circuit Short to Battery
C177012 No.4 Solenoid Circuit Circuit Short to Battery

DESCRIPTION

The NO. 3 height control valve (NO. 1 height control compressor) opens and closes the right and left circuit lines to pneumatic cylinder assembly with shock absorber of each wheel independently using the signal from the suspension control ECU.

DTC NO. Detection Item DTC Detection Condition Trouble Area Warning Indicate Memory
C176712 No.1 Solenoid Circuit Circuit Short to Battery With the NO. 3 height control valve (NO. 1 height control compressor) activated, a short signal of the NO. 3 height control valve (NO. 1 height control compressor) is detected for 1 second or more.

  • Wire harness or connector

  • NO. 3 height control valve (NO. 1 height control compressor)

  • Suspension control ECU

 Comes on Yes
C176A12 No.2 Solenoid Circuit Circuit Short to Battery With the NO. 3 height control valve (NO. 1 height control compressor) activated, a short signal of the NO. 3 height control valve (NO. 1 height control compressor) is detected for 1 second or more.

  • Wire harness or connector

  • NO. 3 height control valve (NO. 1 height control compressor)

  • Suspension control ECU

 Comes on Yes
C176D12 No.3 Solenoid Circuit Circuit Short to Battery With the NO. 3 height control valve (NO. 1 height control compressor) activated, a short signal of the NO. 3 height control valve (NO. 1 height control compressor) is detected for 1 second or more.

  • Wire harness or connector

  • NO. 3 height control valve (NO. 1 height control compressor)

  • Suspension control ECU

 Comes on Yes
C177012 No.4 Solenoid Circuit Circuit Short to Battery With the NO. 3 height control valve (NO. 1 height control compressor) activated, a short signal of the NO. 3 height control valve (NO. 1 height control compressor) is detected for 1 second or more.

  • Wire harness or connector

  • NO. 3 height control valve (NO. 1 height control compressor)

  • Suspension control ECU

 Comes on Yes

WIRING DIAGRAM

B004S99E01

CAUTION / NOTICE / HINT

Note


  • Before performing troubleshooting, inspect the connectors of related circuits.

  • After replacing the suspension control ECU with a new one, perform vehicle height offset.

    Click here

PROCEDURE


  1. INSPECT NO. 3 HEIGHT CONTROL VALVE (NO. 1 HEIGHT CONTROL COMPRESSOR)


    1. Inspect the NO. 3 height control valve (NO. 1 height control compressor).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 1 HEIGHT CONTROL COMPRESSOR Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (NO. 3 HEIGHT CONTROL VALVE (NO. 1 HEIGHT CONTROL COMPRESSOR) - SUSPENSION CONTROL ECU)


    1. Turn the power switch off.

    2. Disconnect the L104 suspension control ECU connector.

    3. C176712 or C176A12 output:


      1. Disconnect the L181 NO. 3 height control valve (NO. 1 height control compressor).

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

        Standard Resistance
        C176712:
        Tester Connection Condition Specified Condition
        L104-11 (SLC1) - L181-1 (SMTI) Always Below 1 Ω
        L104-11 (SLC1) or L181-1 (SMTI) - Body ground and other terminals Always 10 kΩ or higher
        C176A12:
        Tester Connection Condition Specified Condition
        L104-12 (SLC2) - L183-3 (SMSI) Always Below 1 Ω
        L104-12 (SLC2) or L181-3 (SMSI) - Body ground and other terminals Always 10 kΩ or higher

    4. C176D12 or C177012 output:


      1. Disconnect the L183 NO. 3 height control valve (NO. 1 height control compressor).

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

        Standard Resistance
        C176D12:
        Tester Connection Condition Specified Condition
        L104-14 (SLC3) - L181-3 (SMTO) Always Below 1 Ω
        L104-14 (SLC3) or L183-3 (SMTI) - Body ground and other terminals Always 10 kΩ or higher
        C177012:
        Tester Connection Condition Specified Condition
        L104-13 (SLC4) - L183-1 (SMOS) Always Below 1 Ω
        L104-13 (SLC4) or L183-1 (SMOS) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SUSPENSION CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR