Code 4/22521

Sensor, general ground faults - testing

Fault symptom

Permanent: 42521
Intermittent: 22521

Conditions
This diagnostic trouble code is generated if the self test program detects 12 V on a general ground cable (0 V cable) for the blended air temperature sensor, pin 22 and cabin temperature sensor, pin 2 together with diagnostic trouble codes 46322 and 46323. Measurement gives less than 12 V. Only one diagnostic trouble code (42521 - 22521).

Testing

ISAT scan tool command: 250

Display shows:
Cabin temperature = +10° C to +40° C

If the display shows +18° C, the fault may be battery positive voltage on pin 2.

ISAT scan tool command:252

Display shows:
Blended air temperature = 0° C to +80° C

If the display shows +50° C (version 2.00) or a fixed value calculated by the Automatic Climate Control (ACC) control module (version 2.01), the fault may be battery positive voltage on pin 22.


Important : At temperatures below 0° C, the cabin temperature sensor and blended air temperature sensor cannot be tested.






Sensor, general ground faults - testing

Action
1 Allow the ACC control module's 39 pin connector to be connected. Switch on the ignition and measure voltage between pin 2 and ground or pin 22 and ground from the rear of the connector.
2 If there is voltage, switch off the ignition, wait for 35 seconds and unplug the 39 pin connector from the ACC control module.
3 Switch on the ignition. If there is still voltage, check the wiring harness to the sensor and the sensor itself.
4 If no voltage is indicated, reinstall connectors and erase diagnostic trouble codes. Restart the system to check if the fault is still present before trying a new ACC control module.