AIR SUSPENSION SYSTEM, Diagnostic DTC:C1792

DTC Code DTC Name
C1792 Height Control Switch Circuit

DESCRIPTION

The vehicle height can be adjusted by pressing the height control switch.

By pressing the "up" side, vehicle height is raised.

By pressing the "down" side, vehicle height is lowered.

DTC Code DTC Detection Condition Trouble Area
C1792 The height control switch signal does not change.

  • Height control switch (combination switch assembly)

  • Harness or connector

  • Suspension control ECU

Tech Tips

This DTC is stored only during test mode.

WIRING DIAGRAM

B001CRFE09
*1 Up
*2 Down
*3 Height Control Switch (Combination Switch Assembly)
*4 Suspension Control ECU

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. READ VALUE USING GTS (HEIGHT CONTROL SWITCH)


    1. Turn the ignition switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / Air suspension / Data List.

      Air Suspension
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Height Control Switch (UP) Height control switch ("up" side) / ON or OFF

      ON: Switch is pressed and held

      OFF: Switch is not pressed

      		 -
      Height Control Switch (DOWN) Height control switch ("down" side) / ON or OFF

      ON: Switch is pressed and held

      OFF: Switch is not pressed

      		 -

    6. Check that the value displayed on the GTS changes by pressing the height control switch "up" side or "down" side.

      OK
      Height control switch value changes.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  2. INSPECT COMBINATION SWITCH ASSEMBLY


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

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

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

    B

    REPLACE COMBINATION SWITCH ASSEMBLY Click here

    A

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


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

    2. Disconnect the A49 suspension control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G156-6 (HI) - A49-15 (UPSW) Always Below 1 Ω
      G156-7 (LO) - A49-14 (DNSW) Always Below 1 Ω
      G156-24 (E) - Body ground Always Below 1 Ω
      G156-6 (HI) or A49-15 (UPSW) - Body ground Always 10 kΩ or higher
      G156-7 (LO) or A49-14 (DNSW) - Body ground Always 10 kΩ or higher

    OK

    REPLACE SUSPENSION CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR