P2162Vehicle Speed Sensor A/B Correlation
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2162 means two speed sources, A and B, disagree by more than the calibration permits although each circuit is electrically sound. Depending on the vehicle, A and B can be a transmission output sensor, a transfer case sensor or wheel sensors read through the ABS unit. No manufacturer documents P2162 publicly. GM shows how closely the sources are linked: when its transfer case sensor fails (P2160/P2161), the software substitutes driven-wheel speed multiplied by the axle ratio (18OBDG04). California's OBD rule names the vehicle speed sensor among inputs that must be checked for plausibility. Wrong tyre size or axle ratio, a damaged tone wheel or debris on one sensor are typical causes. Speedometer, shifting, cruise control and 4WD may suffer.
- What you may notice
- Check engine lamp
- Speedometer reading wrong or unsteady
- Harsh or mistimed shifts, possibly a fixed-gear fallback
- Likely causes
- LikelyTyre size or axle ratio differs from the programmed values
- PossibleMetal debris or damage on one of the two sensors
- PossibleDamaged or wrong tone wheel on one shaft or hub
- RareWheel speed signal from the ABS unit faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.