What it means
The reported transmission output shaft speed does not correlate with wheel speed within the expected range.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The module compares transmission output shaft speed with wheel speed reported by the ABS sensors to check whether the drivetrain and wheels are turning in a plausible relationship. P215C sets when those readings disagree beyond the permitted range, pointing to a speed signal, wheel encoder, or driveline problem.
Common causes
Most likely first.
- Faulty output shaft speed sensor or wheel speed sensor
- Damaged wiring or connectors in either sensor circuit
- Damaged tone ring or wheel speed encoder
- Transmission or driveline fault
Symptoms
- Check engine light on
- ABS or traction-control warning light may come on
- Speedometer may read inaccurately
- Transmission shifting may be affected
How to diagnose it
- Review freeze-frame data and live scan readings for output shaft speed and each wheel-speed sensor to see which value first diverges.
- Check that tyre sizes and wear are consistent with the vehicle's specified setup.
- Inspect wheel-speed sensor wiring, connectors, and tone rings or encoders for damage, corrosion, debris, or looseness.
- Graph output shaft and wheel speeds during a safe road test, watching for dropouts or sudden spikes in one signal.
- Test the suspect speed sensor and its wiring to the manufacturer's specification; if signals are sound, check for transmission or driveline faults.
Common fixes
- Clean and reconnect a loose or contaminated sensor connector.
- Repair damaged wiring at the affected wheel-speed or output shaft sensor.
- Replace the sensor that fails circuit or signal testing.
- Repair a damaged tone ring or wheel-speed encoder.
- Correct the identified transmission or driveline fault.
Can I keep driving?
If ABS or traction-control warnings accompany this code, those systems may not work as intended, so drive cautiously and leave extra stopping distance. Avoid continued driving if shifting becomes erratic or speed readings drop out.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.