B1422

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

SYSTEM DESCRIPTION

The ECM sends an 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 locks, and turns the magnetic clutch off.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

(a) Use 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 AIR CONDITIONING AMPLIFIER

(a) Remove the A/C amplifier with the connectors still connected.





(b) Measure the waveform of the connector.









Standard:





Result:





C -- REPLACE AIR CONDITIONING AMPLIFIER

B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.

3. INSPECT COMPRESSOR AND MAGNETIC CLUTCH (A/C LOCK SENSOR)

(a) Disconnect the connector from the A/C compressor.





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

Standard resistance:





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

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

(a) Disconnect the connector from the A/C amplifier.





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





Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE AIR CONDITIONING AMPLIFIER