AIR SUSPENSION SYSTEM, Diagnostic DTC:C1799

DTC Code DTC Name
C1799 Luggage Room Mode Switch Circuit (Test Mode DTC)

DESCRIPTION

Pressing the height control switch (luggage compartment) for approximately 1 second switches modes. This switch can be operated with the power switch on or off, the shift lever in P and the back door open. When the power switch is off, this switch can be only be used to lower the vehicle height. If the switch is pressed while the vehicle height is changing, vehicle height control will be cancelled.

DTC No. DTC Detecting Condition Trouble Area
C1799 Detected only during Test Mode.

  • Height control switch (luggage compartment)

  • Harness or connector

  • Suspension control ECU

WIRING DIAGRAM

A01NFVZE02

INSPECTION PROCEDURE

Note


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

  • Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation Click here; 2) DTC inspection Click here; and 3) Intelligent tester inspection (Data List or Active Test) Click here. If no malfunctions are found in other areas, replace the suspension control ECU.

  • If the suspension control ECU is replaced, the vehicle height offset calibration and registration of vehicle identification information must be performed Click here and Click here

PROCEDURE


  1. INSPECT HEIGHT CONTROL SWITCH (LUGGAGE COMPARTMENT)


    1. A01NDY3E03
      Text in Illustration
      *1

      Component without harness connected

      (Height Control Switch)

      Disconnect the height control switch (luggage compartment) connector.

    2. Measure the resistance according to the values in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      1 (LSW) - 8 (IGH) Height control switch while pressing "UP" button 10 kΩ or higher
      Height control switch while pressing "DOWN" button Below 1 Ω
      Neutral position 10 kΩ or higher
      2 (HSW) - 8 (IGH) Height control switch while pressing "UP" button Below 1 Ω
      Height control switch while pressing "DOWN" button 10 kΩ or higher
      Neutral position 10 kΩ or higher

    NG

    REPLACE HEIGHT CONTROL SWITCH (LUGGAGE COMPARTMENT) Click here

    OK

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


    1. A01NGDOE04
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Height Control Switch)
      *2

      Rear view of wire harness connector

      (to Suspension Control ECU)

      Disconnect the A56 ECU connector.

    2. Disconnect the O26 height control switch (luggage compartment) connector.

    3. Measure the resistance according to the values in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      O26-1 (LSW) - A56-22 (LDNS) Always Below 1 Ω
      O26-2 (HSW) - A56-23 (LUPS) Always Below 1 Ω
      A56-22 (LDNS) - Body ground Always 10 kΩ or higher
      A56-23 (LUPS) - Body ground Always 10 kΩ or higher
      Result
      Condition Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE SUSPENSION CONTROL ECU (for RHD) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE SUSPENSION CONTROL ECU (for LHD) Click here