AIR SUSPENSION SYSTEM, Diagnostic DTC:C1747/47

DTC Code DTC Name
C1747/47 Leveling Solenoid Valve Circuit

DESCRIPTION

The suspension control ECU opens the leveling solenoid valve (No. 2 height control valve) to allow compressed air to flow into the height control cylinder (pneumatic cylinder) and raise the vehicle height.

The No. 2 height control valve consists of a leveling solenoid valve and a gate solenoid valve.

The leveling solenoid valve opens and closes the passage between the height control compressor and the height control cylinder (pneumatic cylinder).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

C1747/47

Leveling Solenoid Valve Circuit

Either condition is met:

  • With the height control valve inactivated, an open signal of the height control valve is detected for 1 second or more.

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

  • Harness or connector

  • Leveling solenoid valve (No. 2 height control valve)

  • Suspension control ECU

Indicated

Tip:
  • Once the suspension control ECU stores DTC C1747/47 in memory, vehicle height control is suspended until a normal signal is input to the suspension control ECU from the height control valves. However, control is resumed if the engine switch is turned off and then on (IG) again.

  • Malfunction in the leveling solenoid valve:

    Height control operation is suspended and the height control indicator does not change by operating the height control switch.

WIRING DIAGRAM

C216269E13

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 C1747/47, perform the inspection necessary for DTC C1782/82 first (Click here).

PROCEDURE

  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR LEVELING 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

      Measurement Item

      Control Range

      Diagnostic Note

      Rear Leveling Solenoid

      Leveling solenoid valve

      ON or OFF

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

      • When the Active Test is performed, Rear Leveling 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 the DTC chart)

      C

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    C

    USE SIMULATION METHOD TO CHECK

    A
  2. CHECK HARNESS AND CONNECTOR (LEVELING SOLENOID VALVE - SUSPENSION CONTROL ECU AND BODY GROUND)

    1. Disconnect the S6 leveling solenoid valve connector.

    2. Disconnect the A11 suspension control ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      S6-3 (RH+) - A11-16 (SLRR)

      Always

      Below 1 Ω

      S6-3 (RH+) - Body ground

      Always

      10 kΩ or higher

      S6-2 (E) - Body ground

      Always

      Below 1 Ω

      Result

      Result

      OK

      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK
  3. INSPECT NO. 2 HEIGHT CONTROL VALVE (LEVELING SOLENOID VALVE)

    1. Turn the engine switch off.

    2. Remove the No. 2 height control valve.

      Click here

    3. C214512C03

      *a

      Component without harness connected

      (No. 2 Height Control Valve)

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      2 (E) - 3 (RH+)

      20°C (68°F)

      10 to 14 Ω

    4. Connect the positive (+) lead of the battery to terminal 3 (RH+) and the negative (-) lead to terminal 2 (E) 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

    NG

    REPLACE NO. 2 HEIGHT CONTROL VALVE ASSEMBLY