Up to 08/2009

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1422/22: Compressor Lock Sensor Circuit
B1422/22 - Compressor Lock Sensor Circuit

SYSTEM DESCRIPTION

The ECM sends the engine speed signal to the A/C amplifier via CAN communication.

The A/C amplifier reads the difference between compressor speed and engine speed. When the difference becomes too large, the A/C amplifier determines that the compressor is locked, and turns the magnetic clutch off.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

(a) Use the Techstream to check if the CAN communication system is functioning normally.

Result:





B -- GO TO CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting
A -- Continue to next step.

2. INSPECT A/C COMPRESSOR (A/C LOCK SENSOR)

(a) Disconnect the A/C compressor connector.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE A/C COMPRESSOR (A/C LOCK SENSOR) Removal
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - A/C LOCK SENSOR)

(a) Disconnect the A/C amplifier connector.





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





Standard Resistance:





Result:





Text in Illustration





C -- REPLACE A/C AMPLIFIER

B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR