Compressor Lock Sensor Circuit - Air Conditioning System

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

DTC 22 - Compressor Lock Sensor Circuit

DESCRIPTION

This sensor sends 4 pulses par engine revolution to the A/C amplifier. If the ratio of the compressor speed divided by the engine speed is smaller than a predetermined value, the A/C amplifier turns the compressor off, and the indicator flashes at about 1 sec. intervals.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT AIR CONDITIONING AMPLIFIER (LOCK)




(a) Remove the A/C amplifier with the connectors still connected.
(b) Turn the ignition switch ON.
(c) Turn the A/C switch ON.




(d) Measure the waveform between terminal LOCK (A16-19) and terminal SG (A16-6) of the A/C amplifier.
OK:
Waveform appears as shown in the illustration.
Result:





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

2. INSPECT COOLER COMPRESSOR ASSEMBLY




(a) Disconnect the connector from the cooler compressor assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE COOLER COMPRESSOR ASSEMBLY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (COOLER COMPRESSOR ASSEMBLY - A/C AMPLIFIER)
(a) Check for open and short circuit in the harness and the connector between the cooler compressor assembly and the A/C amplifier Electronic Circuit Inspection Procedure.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AIR CONDITIONING AMPLIFIER