Air Conditioning Cut Control Circuit

DESCRIPTION

This circuit cuts air conditioning operation during vehicle acceleration in order to increase acceleration performance. During acceleration with the vehicle speed at 30 km/h (19 mph) or less and accelerator pedal opening angle at 45° or more, the A/C magnetic switch is turned off for several seconds.

The air conditioning is also controlled by the ECM outputting the engine coolant temperature to A/C amplifier.

WIRING DIAGRAM

INSPECTION PROCEDURE

When using intelligent tester:

PROCEDURE

READ VALUE USING INTELLIGENT TESTER (CHECK OPERATION AIR CONDITIONING CUT CONTROL)
1. Connect the intelligent tester to the DLC3.
2. Start the engine and air conditioning switch ON.
  
  Tech Tips
  
  A/C magnetic clutch is turned ON.
3. Enter the following menus: Powertrain / Engine and ECT / Active Test / A/C Cut SIG.
4. Check operation of A/C magnetic clutch cut when air conditioning cut control is operated by the intelligent tester.
  
  OK
  
  A/C magnetic clutch is turned OFF.
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

NG

OK
A/C magnetic clutch is turned OFF.

INSPECT ECM (ACT VOLTAGE)

Start the engine.

Measure the voltage of the ECM connector.

Standard voltage

Tester Connection	Condition	Specified Condition
E21-8 (ACT) - Body ground	Engine at idling	9 to 14 V
E21-8 (ACT) - Body ground	Ignition switch ON, Engine stopped	0 to 3 V

OK

REPLACE ECM

NG

CHECK WIRE HARNESS (ECM - AIR CONDITIONING AMPLIFIER)

Disconnect the A9 A/C amplifier connector.
Disconnect the E21 ECM connector.

Measure the resistance of the wire harness side connectors.

Standard resistance

Tester Connection	Specified Condition
A9-2 (ACT)* - E21-8 (ACT)	Below 1 Ω
E21-8 (ACT) - Body ground	10 kΩ or higher

Tech Tips

*: Terminal arrangement Click here.

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

CHECK AND REPLACE AIR CONDITIONING AMPLIFIER

When not using intelligent tester: