Air Suspension System

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1752/52: Compressor Motor Malfunction
C1752/52 - Compressor Motor Malfunction

DESCRIPTION

When the "up" side of the height control switch is pressed, a signal is sent from terminal RC of the suspension control ECU to switch the AIR SUS relay on. As a result, the relay contacts close and the compressor motor turns on, producing compressed air.

The suspension control ECU detects the amount of current flowing to the compressor motor by means of the differences in potential at terminals RM+ and RM- of the suspension control ECU. In this way, the suspension control ECU monitors the compressor motor circuit for abnormalities.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the suspension control ECU, perform registration Testing and Inspection.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT
If DTC C1782/82 is output at the same time as C1752/52, perform the inspection necessary for DTC C1782/82 first C1782.

PROCEDURE

1. INSPECT SUSPENSION CONTROL RELAY (AIR SUS) C1751

NG -- REPLACE SUSPENSION CONTROL RELAY (AIR SUS)
OK -- Continue to next step.

2. CHECK TERMINAL VOLTAGE (POWER SUPPLY)

(a) Remove the AIR SUS relay from the engine room relay block.





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

Standard Voltage:





Text in Illustration





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

3. CHECK HARNESS AND CONNECTOR (HEIGHT CONTROL COMPRESSOR - AIR SUS RELAY/SUSPENSION CONTROL ECU AND BODY GROUND)

(a) Disconnect the S10 height control compressor connector.

(b) Remove the AIR SUS relay from the engine room relay block.

(c) Disconnect the A11 suspension control ECU 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. INSPECT HEIGHT CONTROL COMPRESSOR (COMPRESSOR MOTOR)

(a) Remove the height control compressor Removal.

(b) Apply 12 V battery voltage to the compressor motor and check the operation of the motor.





OK:





Text in Illustration





NOTICE:
* Do not allow the compressor motor to operate for approximately 90 seconds or more.
* If the compressor is shorted, locked or has a similar type of malfunction, a large amount of current is flowing. Therefore, if the motor does not operate, immediately stop this inspection.
NG -- REPLACE HEIGHT CONTROL COMPRESSOR ASSEMBLY Removal

OK -- REPLACE SUSPENSION CONTROL ECU Removal