Up to 08/2009

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1752: Height Control Compressor Motor Circuit Malfunction
C1752 - Height Control Compressor Motor Circuit Malfunction

DESCRIPTION

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





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)
HINT
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. INSPECT AIR SUS RELAY

(a) Turn the engine switch off.

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





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

Standard resistance:





NG -- REPLACE AIR SUS RELAY
OK -- Continue to next step.

2. INSPECT HEIGHT CONTROL COMPRESSOR ASSEMBLY (COMPRESSOR MOTOR)

(a) Disconnect the compressor motor connector.

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





(c) Check the operation of the compressor motor.

OK:

Motor operates

Text in Illustration





NOTICE:
- 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 Removal
OK -- Continue to next step.

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

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





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

Standard voltage:





Text in Illustration





(c) Disconnect the P24 compressor connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

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

(a) Disconnect the A55 ECU connector.





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

Standard resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE SUSPENSION CONTROL ECU