Compressor Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM: Compressor Circuit

Compressor Circuit

DESCRIPTION

The A/C amplifier outputs the magnetic clutch ON signal from AC1 terminal to the ECM. When the ECM receives this signal, it sends a signal from ACT terminal and the A/C amplifier switches the A/C magnetic clutch relay ON. This turns the A/C magnetic clutch on.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON and push the Techstream main switch on.
(c) Check the A/C magnetic clutch input signal using Data List.

Engine and ECT





NG -- CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER (AC1 TERMINAL) - ECM (AC1 TERMINAL))
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON and push the Techstream main switch on.
(c) Check the A/C magnetic clutch operation permission signal using Data List.

Engine and ECT





NG -- REPLACE ECM
OK -- Continue to next step.

3. PERFORM ACTIVE TEST USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON and push the Techstream main switch on.
(c) Check the A/C magnetic clutch operation using Active Test.

Air Conditioner





NG -- INSPECT COOLER RELAY ASSEMBLY (MG CLT RELAY)
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER (ACT TERMINAL) - ECM (ACT TERMINAL))
(a) Check for open and short circuit in the harness and the connector between the A/C amplifier and the ECM Electronic Circuit Inspection Procedure.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

5. INSPECT COOLER RELAY ASSEMBLY (MG CLT RELAY)




(a) Remove the cooler relay assembly (MG CLT relay) from the engine room J/B.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPLACE COOLER RELAY ASSEMBLY (MG CLT RELAY)
OK -- Continue to next step.

6. INSPECT MAGNETIC CLUTCH ASSEMBLY




(a) Disconnect the connector from the cooler compressor assembly.
(b) Connect the battery positive (+) lead to terminal 3, check that the following occurs: 1) the magnetic clutch's operating sound can be heard, and 2) the magnetic clutch's hub and rotor lock.

NG -- REPLACE MAGNETIC CLUTCH ASSEMBLY
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER (MGC TERMINAL) - BODY GROUND)
(a) Check for open and short circuit in the harness and the connector between the A/C amplifier and body ground Electronic Circuit Inspection Procedure.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AIR CONDITIONING AMPLIFIER
8. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER (AC1 TERMINAL) - ECM (AC1 TERMINAL))
(a) Check for open and short circuit in the harness and the connector between the A/C amplifier and the ECM Electronic Circuit Inspection Procedure.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

9. INSPECT AIR CONDITIONING AMPLIFIER (AC1)




(a) Remove the A/C amplifier with the connectors still connected.
(b) Start the engine and push AUTO switch.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- REPLACE ECM