B1422

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 air conditioning amplifier assembly via CAN communication.

The air conditioning amplifier assembly reads the difference between compressor speed and engine speed. When the difference becomes too large, the air conditioning amplifier assembly 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 AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Remove the air conditioning amplifier assembly with its connectors still connected Removal.





(b) Measure the waveform of the connector.

Measurement Condition





OK:

Waveform is as shown in the illustration.

NG -- INSPECT COOLER COMPRESSOR ASSEMBLY (A/C LOCK SENSOR)

OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

3. INSPECT COOLER COMPRESSOR ASSEMBLY (A/C LOCK SENSOR)

(a) Disconnect the C37 cooler compressor assembly connector.





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

Standard Resistance:





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

4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - COOLER COMPRESSOR)

(a) Disconnect the E35 amplifier connector.





(b) Disconnect the C37 cooler compressor assembly connector.

(c) 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 ASSEMBLY Removal