AIR SUSPENSION SYSTEM, Diagnostic DTC:C1782

DTC Code DTC Name
C1782 Power Source Voltage Malfunction

DESCRIPTION

DTC No. DTC Detection Condition Trouble Area
C1782

When one of the following conditions is met:


  • IG terminal voltage is 10 V or less or 16 V or more continuously for 0.5 seconds

  • BAT terminal voltage is 10 V or less or 16 V or more continuously for 0.5 seconds

  • Signals are sent from the wheel speed sensor for 5 seconds although the ECU determines that the power switch is off.

  • Auxiliary battery

  • Charging system

  • ECU IG1 Fuse

  • AIR SUS Fuse

  • Wire harness or connector

  • Suspension control ECU

WIRING DIAGRAM

A01NCZ1E03

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

Tech Tips

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (IG AND +B POWER SOURCE VOLTAGE)


    1. Turn the power switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the power switch on (IG) and the intelligent tester on.

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

    5. According to the display on the intelligent tester.

      Air suspension system
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      IG Power Source Voltage

      ECU power supply voltage /

      min.: 0 V

      max.: 255 V

      		 Actual ECU power supply voltage: 11 to 14 V -
      +B Power Source Voltage

      ECU power supply voltage /

      min.: 0 V

      max.: 255 V

      		 Actual ECU power supply voltage: 11 to 14 V -
      OK
      11 to 14 V
      Result
      Result Proceed to
      NG A
      OK B

    B

    CHECK DTC Click here

    A

  2. CHECK AUXILIARY BATTERY


    1. Measure the auxiliary battery voltage.

      Standard voltage
      Tester Connection Condition Specified Condition
      Auxiliary battery terminal Always 11 to 14 V

    NG

    GO TO CHARGING SYSTEM Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF ECU)


    1. A01NE3EE25
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Suspension Control ECU)

      Disconnect the A56 ECU connector.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      A56-3 (BAT) - Body ground Always 11 to 14 V
      A56-1 (IG) - Body ground Power switch on (IG) 11 to 14 V

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A56-5 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK DTC


    1. Clear the DTC Click here.

    2. Check for DTC Click here.

      Result
      Condition Proceed to
      DTC is output (for LHD) A
      DTC is output (for RHD) B
      DTC is not output C

    B

    REPLACE SUSPENSION CONTROL ECU (for RHD) Click here

    C

    USE SIMULATION METHOD TO CHECK Click here

    A

    REPLACE SUSPENSION CONTROL ECU (for LHD) Click here