Compressor Circuit

AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): Compressor Circuit

Compressor Circuit

DESCRIPTION

The A/C amplifier outputs the magnetic clutch ON signal from terminal AC1 to the ECM receives this signal, it sends a signal from terminal ACMG (MGC) and switches the magnetic clutch relay ON, thus turning on the magnetic clutch.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE OF TECHSTREAM
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn Techstream on.
(c) Select the item below in the Data List, and read the display on Techstream.

Data List / Engine and ECT:





NG -- CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONING AMPLIFIER)
OK -- Continue to next step.
2. PERFORM ACTIVE TEST BY TECHSTREAM
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn Techstream on.
(c) Select the item below in the Active Test and then check that the relay operates.

Active Test / Engine and ECT:





NG -- INSPECT MAGNETIC CLUTCH RELAY
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3. INSPECT MAGNETIC CLUTCH RELAY





(a) Remove the relay (magnetic clutch relay) from the engine room R/B.
(b) Measure the resistance according to the value(s) in the table below
Standard resistance:





NG -- REPLACE MAGNETIC CLUTCH RELAY
OK -- Continue to next step.
4. INSPECT AIR CONDITIONING AMPLIFIER (MGC - BODY GROUND)





(a) Remove the A/C amplifier.
(b) Disconnect the connector.
(c) Start the engine and turn the A/C switch on.
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT AIR CONDITIONING AMPLIFIER (MGC - BODY GROUND)





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





NG -- CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONING AMPLIFIER)
OK -- Continue to next step.
6. INSPECT MAGNETIC CLUTCH ASSEMBLY
(a) Disconnect the connector from the magnetic clutch assembly.





(b) Connect the positive (+) lead from the battery to terminal A2-3 and negative (-) lead to body ground, then check that the magnetic clutch assembly is engaged.
NG -- REPLACE MAGNETIC CLUTCH ASSEMBLY
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (MAGNET CLUTCH ASSEMBLY - BODY GROUND)





(a) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - MAGNET CLUTCH ASSEMBLY)





(a) Disconnect the connector from the A/C amplifier.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONING AMPLIFIER)





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





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. INSPECT AIR CONDITIONING AMPLIFIER





(a) Remove the ECM with the connectors still connected.
(b) Start the engine and turn the A/C switch on.
(c) Measure the voltage according to the condition(s) in the table below.
Standard voltage:





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