Up to 08/2009

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1743,C1744: Rear Height Control Solenoid Valve RH Circuit Malfunction


DESCRIPTION

The No. 2 height control valve independently opens and closes the left and right air passages to the rear pneumatic cylinders according to the signals from the suspension control ECU.





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 How To Proceed With Troubleshooting; 2) DTC inspection Reading and Clearing Diagnostic Trouble Codes; and 3) Techstream inspection (Data List or Active Test) Scan Tool Testing and Procedures. 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 Calibration and Registration)
PROCEDURE

1. INSPECT HEIGHT CONTROL VALVE NO. 2

(a) Disconnect the rear height control valve No. 2 connector.





(b) Measure the resistance according to the values in the table below.

Standard resistance:

C1743:





C1744:





Text in Illustration





(c) Check the RH valve (C1743).

(1) Connect a positive (+) lead from the battery to terminal 3 (RH+) and a negative (-) lead to terminal 2 (E).

(2) Check the operating sound of the height control valve No. 2.

OK:

It makes an operating sound (click).

(d) Check the LH valve (C1744).

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

(2) Check the operating sound of the height control valve No. 2.

OK:

It makes an operating sound (click).

NG -- REPLACE HEIGHT CONTROL VALVE NO. 2
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (REAR HEIGHT CONTROL VALVE - ECU AND BODY GROUND)

(a) Disconnect the A55 ECU connector.

(b) Disconnect the Q1 height control valve No. 2 connector.

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





Standard resistance:

C1743:





C1744:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE SUSPENSION CONTROL ECU