C0234Wheel Speed Sensor Frequency Error
- Generic OBD-II code · Chassis
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- C0234 is publicly unverifiable: the publicly available J2012 tables, NHTSA's bulletins and maker indexes all lack it; in AA1Car's list of GM ABS codes the same wording belongs to C0245. The title describes a speed signal whose frequency is implausible. The control module derives wheel speed from frequency alone: the inductive sensors of the Saab 9-5 with a 29-tooth ring give roughly 70 Hz at 20 km/h, and the Hall sensors of the 9-3 run on a 48-pole ring up to about 2000 Hz. A frequency far off those of the remaining wheels points to a wrong tone ring, a mismatched tyre size or missing teeth. Nisshinbo patented a test that compares every pulse period with a reference at steady speed; a gap of three or five periods marks one or two broken teeth.
- What you may notice
- ABS and traction lamps on, sometimes only above a certain speed
- Unwanted ABS or traction intervention
- Likely causes
- LikelyDamaged, cracked or wrong tone ring (missing teeth, wrong tooth count)
- PossibleTyre or wheel size differs from the other wheels
- PossibleExcessive air gap or metal debris on the sensor
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.