AIR SUSPENSION SYSTEM, Diagnostic DTC:C1752

DTC Code DTC Name
C1752 Height Control Compressor Motor Circuit Malfunction

DESCRIPTION

The signal from the suspension control ECU turns on the AIR SUS relay. At that time, auxiliary battery voltage is input to the height control compressor motor through the AIR SUS relay. The height control compressor motor starts.

DTC No. DTC Detection Condition Trouble Area
C1752 With the AIR SUS relay activated, a lock signal of the height control compressor motor is detected for 4 sec. or more.

  • AIR SUS relay

  • AIR SUS fusible link

  • Height control compressor assembly (compressor motor)

  • Wire harness or connector

  • Suspension control ECU

WIRING DIAGRAM

A01NDGTE02

INSPECTION PROCEDURE

Note


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

  • If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first Click here.

  • 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. INSPECT AIR SUS RELAY


    1. Turn the power switch off.

    2. A01NDCGE01

      Remove the AIR SUS relay from the engine room J/B.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      3 - 5 When battery voltage is not applied between terminals 1 and 2 10 kΩ or higher
      When battery voltage is applied between terminals 1 and 2 Below 1 Ω

    NG

    REPLACE AIR SUS RELAY

    OK

  2. INSPECT HEIGHT CONTROL COMPRESSOR ASSEMBLY (COMPRESSOR MOTOR)


    1. Disconnect the compressor motor connector.

    2. A01NG6NE03
      Text in Illustration
      *1

      Component without harness connected

      (Compressor Motor)

      Connect a positive (+) lead from the battery to terminal 1 (B) and a negative (-) lead to terminal 2 (E).

    3. Check the operation of the compressor motor.

      OK
      Motor operates

      Note


      • Do not operate the height control compressor for 60 seconds or more.

      • Stop applying voltage immediately if the compressor stops operating because a short will occur and the compressor motor will lock up, causing the flow of excessive current.


    NG

    REPLACE HEIGHT CONTROL COMPRESSOR ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF COMPRESSOR MOTOR)


    1. Remove the AIR SUS relay from the engine room J/B.

      A01NG2DE03

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

      Standard voltage
      Tester Connection Condition Specified Condition
      J/B AIR SUS relay terminal 5 - Body ground Always 11 to 14 V
      Text in Illustration
      *1

      Component without relay

      (Engine Room J/B)

      		 *2

      Front view of wire harness connector

      (to Compressor Motor)
      *3 AIR SUS relay - -

    3. Disconnect the P24 compressor connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      J/B AIR SUS relay terminal 3 - P24-1 (B) Always Below 1 Ω
      P24-1 (B) - Body ground Always 10 kΩ or higher
      P24-2 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (COMPRESSOR MOTOR LOCK DETECTION CIRCUIT)


    1. A01NDNVE02
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Suspension Control ECU)

      Disconnect the A55 ECU connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A55-19 (RM+) - A55-17 (RM-) Always 6.4 to 7.4 mΩ
      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