P1455

P1455
A/C compressor control - Interruption.

P1456
A/C compressor control - upper limit exceeded.

P1457
A/C compressor control - below lower limit.

Function:
The magnetic clutch for the A/C compressor is supplied with battery voltage via a relay.
The coil of the relay is supplied with battery voltage by the ECM on one side and with ground by the ECM on the other. The diagnosis only monitors the wiring from the ECM, pin 62 to the A/C relay, terminal 85.

Diagnostic Condition:
A fault is recognized and stored in memory when the engine speed is above 80 rpm and the battery voltage is between 7.5 Volt and 17 Volt.

Wiring Diagram:




Diagnostic Procedure:

DTC P1455:

DTC P1456:

DTC P1457:

1. Check control wire for A/C relay, pin 2 for interruptions.
1. Remove A/C relay.
2. Connect special tool 9616 to wiring harness.
3. Connect ohmmeter to special tool 9616, pin 62 and to A/C relay pin 2.

Specified Value: 0 - 5 Ohms.

NOTE: The control wire is routed via connector X 59 pin 9.

2. Check control wire for A/C relay, pin 2 for short circuit to B+.
1. Remove A/C relay.
2. Remove control module connector on ECM.
3. Connect voltmeter (plus) to pin 2 at A/C relay arid ground.

Specified Value: 0 Volt.

If meter reads battery voltage, check wiring harness for chafing and pinching damage.

3. Check control wire for A/C relay, pin 2 (terminal 85) for short circuit to ground.
1. Remove A/C relay.
2. Remove ECM connector.
3. Connect ohmmeter to ground and pin 2 (terminal 85).

Specified Value: Infinite Ohms.

If meter reads 0 - 5 Ohms, check wiring harness for chafing or pinching damage.