C0633Front Half Shaft Speed Sensor
- Generic OBD-II code · Chassis
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- On all-wheel-drive systems that can uncouple the front axle, a speed sensor on a front shaft tells the controller how fast the uncoupled part turns, so it can match speeds before re-engaging. A BorgWarner patent uses a Hall sensor on the shift sleeve to read both speed and position and engages once the gap to wheel speed is within about ±100–200 rpm; an American Axle patent uses a pinion speed sensor the same way before moving its shift collar. Ford documents C0633 in the AWD module of 2020 Explorer, Aviator and Police Interceptor Utility 4WD built up to 20 Mar 2020: warning messages with C0633, C00A6:07 or both came from an oil-soaked front halfshaft speed sensor; TSB 21-2270 replaces it (0.8 h).
- What you may notice
- AWD or 4WD warning messages in the cluster
- All-wheel drive limited or not engaging
- Possible oil seepage near the sensor
- Likely causes
- LikelySensor contaminated with axle oil (Ford Explorer/Aviator 2020)
- PossibleFailed sensor or damaged wiring and connector
- RareWrong air gap or damaged sensor target on the shaft
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.