P0878
PowertrainTransmission Pressuremoderate severityTransmission Fluid Pressure Sensor/Switch D Circuit High
What P0878 Means
The transmission fluid pressure sensor D circuit is reporting a voltage that is too high. This usually points to an open circuit or sensor failure.
Symptoms
- Erratic shifting
- Transmission warning light
- Poor shift quality
Common Causes
- Open circuit in wiring
- Failed pressure sensor
- Corroded connector
- Internal transmission fault
Diagnostic Steps
- Inspect wiring for open circuit
- Check connector for corrosion
- Measure sensor voltage with scan tool
- Compare reading to actual pressure
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