AIR SUSPENSION SYSTEM, Diagnostic DTC:C1745/45

DTC Code DTC Name
C1745/45 Exhaust Solenoid

DESCRIPTION

The suspension control ECU operates the exhaust solenoid valve (height control compressor), releases the air from the height control cylinder assembly (pneumatic cylinder) and lowers the vehicle height.

When the vehicle height is lowered, the suspension control ECU opens the height control valve and then operates the exhaust solenoid valve to release compressed air to the outside.

The exhaust solenoid valve is on the compressor unit and has only one valve.

DTC Code DTC Detection Condition Trouble Area
C1745/45

Either condition is met:


  • With the exhaust solenoid valve not activated, an open signal of the exhaust solenoid valve is detected for 1 second or more.

  • With the exhaust solenoid valve activated, a short signal of the exhaust solenoid valve is detected 8 times successively.

  • Harness or connector

  • Exhaust solenoid valve (Height control compressor)

  • Suspension control ECU

Tech Tips


  • Once the suspension control ECU stores DTC C1745/45 in memory, vehicle height control is suspended until a normal signal is input to the suspension control ECU from the exhaust solenoid valve. However, control is resumed if the ignition switch is turned off and then to ON again.

  • Malfunction in the exhaust solenoid valve:

    Height control indicator N comes on or blinks and HI and LO do not come on by operating the height control switch "up" or "down".

WIRING DIAGRAM

A01DP8BE04

INSPECTION PROCEDURE

Note

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

Tech Tips

If DTC C1782/82 is output at the same time as C1745/45, perform the inspection necessary for DTC C1782/82 first Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (EXHAUST SOLENOID)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Chassis / Air suspension / Active Test.

      Air Suspension
      Tester Display Test Part Control Range Diagnostic Note
      Exhaust Solenoid Exhaust solenoid valve ON or OFF

      • The operating sound of the solenoid (clicking sound) can be heard.

      • When the Active Test is performed, Exhaust Solenoid in the Data List changes between ON and OFF accordingly.
      OK
      Operation of solenoid (clicking sound) can be heard.
      Result
      Result Proceed to
      NG A
      OK (When troubleshooting according to problem symptoms table) B
      OK (When troubleshooting according to DTC chart) C

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    USE SIMULATION METHOD TO CHECK Click here

    A

  2. CHECK HARNESS AND CONNECTOR (EXHAUST SOLENOID VALVE - SUSPENSION CONTROL ECU)


    1. Disconnect the S10 exhaust solenoid valve connector.

    2. Disconnect the R19 suspension control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S10-2 (L) - R19-9 (SLEX) Always Below 1 Ω
      S10-2 (L) - Body ground Always 10 kΩ or higher
      S10-1 (B) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT HEIGHT CONTROL COMPRESSOR (EXHAUST SOLENOID VALVE)


    1. Turn the ignition switch off.

    2. Remove the height control compressor Click here.

    3. A01DN5NE02
      Text in Illustration
      *a

      Component without harness connected

      (Exhaust Valve)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (L) - 1 (B) 20°C (68°F) 10 to 14 Ω

    4. Connect the positive (+) lead of the battery to terminal 2 (L) and the negative (-) lead to terminal 1 (B) of the solenoid valve connector. Then check that the valve makes an operating sound.

      OK
      Operation of solenoid (clicking sound) can be heard.

    NG

    REPLACE HEIGHT CONTROL COMPRESSOR ASSEMBLY Click here

    OK

    REPLACE SUSPENSION CONTROL ECU Click here