Air Conditioning System

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

DTC B1422/22 - Compressor Lock Sensor Circuit

DESCRIPTION

This sensor sends 1 pulse per engine revolution to the ECM.
If the ratio between engine and compressor speed deviates 20% or more compared to normal operation, the ECM turns the cooler compressor off and the indicator blinks at approximately 1 second intervals.
The ECM informs the A/C amplifier of the operation condition of the cooler compressor through multiplex communication (CAN and BEAN).






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT ECM




(a) Remove the ECM with its connectors still connected.
(b) Measure the waveform of the connector.
Standard voltage:










Result:





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

2. INSPECT A/C COMPRESSOR (LOCK SENSOR)




(a) Disconnect the E46 A/C compressor connector.
(b) Measure the resistance of the sensor.
Standard resistance:






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

3. CHECK WIRE HARNESS (ECM - A/C COMPRESSOR)




(a) Disconnect the E46 A/C compressor connector.
(b) Disconnect the E8 ECU connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE ECM