The computer sees a missing or wrong signal from the output speed sensor. The driver may notice harsh shifts, a dead speedometer or a stuck gear.
Likely causes, most common first
- Faulty output speed sensor
- Damaged wiring or connector
- Low or dirty transmission fluid
- Metal debris on the sensor
Parts usually involved
- Output speed sensor
- Sensor connector
- Transmission fluid
Test before you replace
Read the output speed live on a road test, compare it with vehicle speed and test the wiring.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.