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 No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

C1745/45

Exhaust Solenoid

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

Indicated
Tip:

  • 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 engine switch is turned off and then on (IG) 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

C216269E11

CAUTION / NOTICE / HINT

Note:

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

Tip:

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 engine switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the intelligent tester on.

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

      Chassis > Air suspension > Active Test

      Tester Display

      Exhaust Solenoid

      Chassis > Air suspension > Active Test

      Tester Display

      Measurement Item

      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 hereClick hereClick here

    A

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

    1. Disconnect the S9 exhaust solenoid valve connector.

    2. Disconnect the R22 suspension control ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      S9-2 (L) - R22-9 (SLEX)

      Always

      Below 1 Ω

      S9-2 (L) - Body ground

      Always

      10 kΩ or higher

      S9-1 (B) - Body ground

      Always

      Below 1 Ω

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT HEIGHT CONTROL COMPRESSOR (EXHAUST SOLENOID VALVE)

    1. Turn the engine switch off.

    2. Remove the height control compressor.

      Click hereClick here

    3. C214511C01

      *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.

      Result

      Result

      OK

      NG
    OK

    REPLACE SUSPENSION CONTROL ECU

    Click here

    NG

    REPLACE HEIGHT CONTROL COMPRESSOR ASSEMBLY

    Click hereClick here