DTC C1751: Compressor Relay Coil Malfunction: Procedure
- CLEAR DTC
- Clear the DTC. Refer to DTC CHECK / CLEAR .
NEXT: Go to next step
- CHECK MOTOR RELAY OPERATION (ACTIVE TEST)
- Turn the power switch OFF.
- Connect the Techstream to the DLC3.
- Turn the power switch ON (IG) and the Techstream ON.
- Enter the following menus: Chassis / Air suspension / Active Test.
- Check the operation sound of the suspension control relay when the solenoid is turned on through the ACTIVE TEST.AIR SUSPENSION
Tester Display Test Part Control Range Diagnostic Note Motor Relay Suspension control relay ON or OFF Operation of solenoid (clicking sound) can be heard OK
Operation of solenoid (clicking sound) can be heard
NG → See step 3
OK → See step 5
- INSPECT SUSPENSION CONTROL RELAY (AIR SUS)
- Turn the power switch OFF.
- Remove the suspension control relay from the engine room No. 5 relay block.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition 3 - 5 When 12 V battery voltage is not applied to terminal 1 and 2 10 kΩ or higher When 12 V battery voltage is applied to terminal 1 and 2 Below 1 Ω
NG → REPLACE SUSPENSION CONTROL RELAY
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL RELAY - ECU AND BODY GROUND)
- Disconnect the L88 ECU connector.
- Remove the suspension control relay from the engine room No. 5 relay block.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition L88-6 (RC) - Relay block suspension control relay terminal 1 Always Below 1 Ω L88-6 (RC) or Relay block suspension control relay terminal 1 - Body ground Always 10 kΩ or higher Relay block suspension control relay terminal 2 - Body ground Always Below 1 Ω
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 6
- USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING
- REPLACE SUSPENSION CONTROL ECU. Refer to REMOVAL