DTC P1456
DTC P1457
1 Check control wire for A/C relay, pin 2, for open circuit.
1. Remove A/C relay.
2. Connect special tool 9637 to wiring harness (DME control module connector).
3. Connect ohmmeter to special tool 9637, pin II/18, and A/C relay, pin 2.
Display: 0 - 5 ohms
2 Check control wire for A/C relay, pin 2, for short circuit to B+.
1. Remove A/C relay.
2. Remove DME control module connector.
3. Connect voltmeter (positive) to A/C relay, pin 2, and ground.
Display: 0 V
If battery voltage is displayed, 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 DME control module connector.
3. Connect ohmmeter to ground and pin 2 (terminal 85).
Display: infinity ohms
If 0 - 5 ohms is displayed, check wiring for chafing and pinching damage.
DME 7.8
P1456
170 A/C compressor control - above limit
Diagnosis conditions
- Engine running
- Battery voltage greater than 7 V
- Air conditioning on
Possible fault cause
- Short circuit to B+ in wiring
Affected terminals
Terminal IV/27
Diagnosis/troubleshooting