A/C Signal: Testing and Inspection

OPERATION
- The air conditioning switch applies the battery voltage to the engine control module when the air conditioning is turned on.
- When the air conditioning ON signal is input, the engine control module drives the idle air control motor and turns ON the power transistor. As a result, the air conditioning power relay coil is energized to turn on the relay switch, which activates the air compressor magnetic clutch.

TROUBLESHOOTING HINTS
If the air compressor magnet clutch is not activated when the air conditioning switch is turned on during idling, faulty air conditioning control system is suspected.

INSPECTION

Using Scan Tool





AIR CONDITIONING SWITCH





AIR CONDITIONING POWER RELAY





HARNESS INSPECTION
Measure the power supply voltage of the air conditioning circuit.
- Air conditioning switch: ON
- Engine control module connector: Disconnected
- Ignition switch: ON
- Dual air conditioning switch: ON
Voltage (V): Battery positive voltage
OK: STOP
NG: Check the air conditioning circuit.

AIR CONDITIONING SWITCH CHECK
Refer to GROUP 55 - Air Conditioning Switch.

AIR CONDITIONING COMPRESSOR CLUTCH RELAY CHECK
Refer to GROUP 55 - On-vehicle service.