P0071

P007100

Diagnostic information - DME control unit

Ambient temperature sensor

DANGER
High voltage.
Death or severe injuries due to high voltage or high current.

- De-energise the vehicle in accordance with the guidelines.
- Work must not be performed on parts carrying a high voltage.

The control unit must be active in order to test internal function sequences and diagnosable inputs/outputs.
In the event of a fault, check whether the fault is permanently >present<. To perform the check, erase the fault memory, meet the diagnostic conditions and read out the fault memory again.

NOTE:
- Comparison of all temperatures with engine that has completely cooled down
- Correctly code auxiliary heater
- No correct determination of outside air temperature
- The displayed value on the instrument cluster does not correspond to the actual outside temperature

Diagnostic conditions
- Comparison of all temperatures with engine that has completely cooled down with terminal 15 on and engine off.

Possible fault causes
- Ambient temperature sensor, implausible signal