P0940moderate severityPowertrain
Hydraulic Oil Temperature Sensor Circuit Low
on 2009 Audi A8 4.2L V8 · AWD
What this code means
The hydraulic oil temperature sensor signal is lower than expected. This usually results from an open circuit or grounded wiring.
Symptoms
- Transmission warning light on
- Poor shift performance
- Incorrect temperature data
Common causes
- Faulty oil temperature sensor
- Open or grounded wiring
- Loose connector
- Control module fault
Diagnostic steps
- Retrieve diagnostic codes
- Inspect wiring for open or ground fault
- Check connector integrity
- Measure sensor resistance
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