C0245Wheel Speed Sensor Frequency Mismatch
- Generic OBD-II code · Chassis
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- C0245 is missing from the reachable J2012 lists but is a documented GM code: PIP5094 lists it, AA1Car's GM table names it Wheel Speed Sensor Frequency Error, and the 2010 and 2011 Saab 9-5 manuals call it Wheel Speed Sensor Frequency Malfunction. The active sensors there get 12 V from the brake module and return a square wave whose frequency gives the wheel speed. The check runs above 9 mph with no open-circuit sensor code, brake released and no cornering; if one wheel differs from the rest by more than 20 percent, ABS, hill start assist, traction and stability control shut down for that ignition cycle and three warning lamps light. GM first checks tyre size and pressure, then the tone ring and sensor seating.
- What you may notice
- ABS, traction/stability and brake warning lamps on together
- ABS, stability control and hill start assist disabled
- Likely causes
- LikelyTyre with wrong size or pressure on one wheel
- PossibleDamaged or contaminated tone ring or magnetic encoder
- PossibleSensor not seated correctly or excessive wheel bearing play
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.