P077C
Output Shaft Speed Sensor Circuit Low
Generic OBD-II
Real-world scan data
Seen in
21
scans in the past year
Found in
<0.1%
of scans
<0.1%
of scans that found faults
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check the wiring and connections of the output shaft speed sensor
- Replace the output shaft speed sensor
- Inspect and repair any damaged or corroded wires in the circuit
- Check and repair any other related sensors or components in the transmission system
Common causes
Most likely first
- Faulty output shaft speed sensor
- Damaged or loose wiring or connectors in the output shaft speed sensor circuit
- Clogged or dirty transmission fluid
- Mechanical issue with the output shaft itself
How to diagnose & fix
Work through it in order
- Decreased fuel efficiency
- Harsh shifting or shifting delay
- Check Engine Light illumination
- Inability to shift gears or transmission slipping
- Loss of power or engine stalling
Read & clear P077C yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.