C1745

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1745: Exhaust Solenoid Valve Circuit Malfunction
C1745 - Exhaust Solenoid Valve Circuit Malfunction

DESCRIPTION

The exhaust valve is installed onto the height control compressor. Based on signals from the suspension control ECU, the exhaust valve opens, which releases the high pressure air within the system out of the vehicle. The exhaust valve operates until the target vehicle height is achieved. When achieved, the height control sensor outputs a signal to the suspension control ECU to stop the operation of the exhaust valve.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
- 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 C1782.
- Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation Electronic Circuit Inspection Procedure; 2) DTC inspection; and 3) the Techstream inspection (Data List or Active Test). If no malfunctions are found in other areas, replace the suspension control ECU.
- If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed Programming and Relearning.

PROCEDURE

1. CLEAR DTC

(a) Clear the DTC Air Suspension System.

NEXT -- Continue to next step.

2. CHECK EXHAUST VALVE OPERATION (ACTIVE TEST)

(a) Turn the power switch OFF.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch ON (IG) and the Techstream ON.

(d) Enter the following menus: Chassis / Air suspension / Active Test.

(e) Check the operation sound of the exhaust valve when the solenoid is turned on through the ACTIVE TEST.

Air Suspension





OK:

Operation of solenoid (clicking sound) can be heard

NG -- INSPECT HEIGHT CONTROL COMPRESSOR (EXHAUST VALVE)

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

3. INSPECT HEIGHT CONTROL COMPRESSOR (EXHAUST VALVE)

(a) Turn the power switch OFF.

(b) Remove the height control compressor Removal.





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

Standard resistance:





NG -- REPLACE HEIGHT CONTROL COMPRESSOR Removal
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (EXHAUST VALVE - ECU AND BODY GROUND)

(a) Turn the power switch OFF.

(b) Disconnect the L88 ECU connector.

(c) Disconnect the A56 exhaust valve connector.

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





Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE SUSPENSION CONTROL ECU Removal