P1458

P1458
AC compressor active Signal - Malfunction
AC compressor signal - implausible operating range

Function
The function "A/C compressor on" is signaled by the climate control regulator to the ECM, (pin 38). The ECM switches the A/C compressor on when the signal for climate readiness is available at the same time (ECM. pin 11). Climate readiness means: condenser fan switched on to stage 1. The requirement for the A/C compressor is monitored for plausibility, meaning that if the climate control is not switched on, the requirement for the climate control must not be called for.

Diagnostic conditions
Continuous monitoring.
During the fuel tank ventilation diagnosis, the A/C compressor is switched off.





Wiring Diagram.





Diagnostics procedure
Check wiring from ECM, pin 11 to climate control regulator connector K 23 for continuity.
1. Remove connector K from climate control regulator.
2. Remove ECM connector.
3. Connect ohmmeter to CM connector, pin 11 and connector K 23.

- Specified value: 0 - 5 ohms
- If meter reads infinite resistance, check connectors X 4/2, pin 9, X 1/1, pin 3 and X 69, pin 3.

Check wiring from ECM to A/C pressure switch for short circuit to ground.
1. Remove connector from A/C connector for A/C pressure switch.
2. Remove ECM connector.
3. Connect ohmmeter to ECM connector, pin 38 and ground.

- Specified value: infinite resistance
- If meter reads 0 - 5 ohms, check wiring harness for chafing or pinching damage.

Check wiring from A/C pressure switch to climate control regulator for short circuit to ground.
1. Remove connector of A/C pressure switch.
2. Remove connector K at climate control regulator.
3. Connect ohmmeter to connector K 24 and ground.

- Specified value: infinite resistance
- If meter reads 0 - 5 ohms, check wiring harness for chafing or pinching damage.

Check climate control regulator.
1. Remove connector for A/C pressure switch.
2. Connect ohmmeter to connected connector K 24 and ground. Climate control is not switched on.

- Specified value: infinite resistance
- If meter reads 0 - 5 ohms, replace climate control regulator.