AIR SUSPENSION SYSTEM, Diagnostic DTC:C1794

DTC Code DTC Name
C1794 Height Control OFF Switch Circuit

DESCRIPTION

If the height control OFF switch is pressed when the vehicle is stopped with the engine running or the ignition switch ON, vehicle height control is disabled and remains disabled even after the ignition switch is turned off. Pressing the height control OFF switch again with the engine running or the ignition switch ON resumes vehicle height control. If the vehicle speed reaches approximately 30 km/h (19 mph) when vehicle height control is disabled, vehicle height control automatically resumes.

DTC Code DTC Detection Condition Trouble Area
C1794 Stored only during test mode.

  • Height control off switch (Combination switch assembly)

  • Harness or connector

  • Suspension control ECU

WIRING DIAGRAM

B001I0LE10

CAUTION / NOTICE / HINT

Note

When replacing the suspension control ECU, perform registration Click here.

PROCEDURE


  1. INSPECT COMBINATION SWITCH ASSEMBLY


    1. Remove the height control off switch (combination switch assembly) Click here.

    2. Inspect the height control off switch (combination switch assembly) Click here.

      Result
      Result Proceed to
      Height control off switch (combination switch assembly) is normal A
      Height control off switch (combination switch assembly) is abnormal B

    B

    REPLACE COMBINATION SWITCH ASSEMBLY Click here

    A

  2. CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH ASSEMBLY - SUSPENSION CONTROL ECU)


    1. Disconnect the A49 suspension control ECU connector.

    2. Disconnect the G156 height control off switch (combination switch assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-13 (TD) - G156-5 (N) Always Below 1 Ω
      A49-13 (TD) or G156-5 (N) - Body ground Always 10 kΩ or higher
      G156-24 (E) - Body ground Always Below 1 Ω

    OK

    REPLACE SUSPENSION CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR