C0039Right Rear Tone Wheel
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- Covers the right rear tone wheel (reluctor or encoder ring) read by the right rear wheel speed sensor, completing the four-corner tone-wheel set with C0030, C0033 and C0036. It is a signal-plausibility code set when the module sees an erratic, noisy or intermittent rear speed signal consistent with a damaged, contaminated or loose tone ring rather than a sensor circuit failure. Ford documents the right rear sensor group including this corner on 2021 Bronco and Ranger vehicles with an illuminated ABS warning. A fault disables ABS, traction and stability control and lights the ABS warning lamp while base braking remains; electronic brake-force distribution is affected where it uses the rear sensors.
- What you may notice
- ABS warning lamp on
- ABS and stability control disabled
- Grinding noise from wheel hub
- Likely causes
- LikelyDamaged or contaminated tone ring
- PossibleLoose or displaced hub bearing
- RareExcessive sensor-to-ring air gap
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.