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Oxygen Sensor Upstream of Catalytic Converter

P003800

Diagnostic information - DME control unit

Oxygen sensor upstream of catalytic converter, oxygen sensor heating

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:
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Diagnostic conditions
- Engine on

Possible fault causes
- Short circuit to B+
- Short circuit to ground
- Electrical fault