P215A: Vehicle Speed - Wheel Speed Correlation

What does P215A mean?

P215A compares the vehicle speed used by the powertrain with the speed derived from the ABS wheel sensors and sets when the two disagree. Volvo and Mack trucks document it most clearly: with I-Shift or mDRIVE gearboxes the code appears once the difference exceeds 12 km/h (7.5 mph), and the advice is to verify the speed factor and the tyre size stored in the brake controller before testing sensors. A Volvo case traced P215A with throttle dropouts to a loose ABS module ground. GM's 2025 brake module tables use P215A, Type B with MIL after two trips, both when more than two wheel sensor signals look suspect at the same time and when the spread between fastest and slowest wheel exceeds about 52 mph while moving. Speedometer loss, cruise or traction faults follow. P215B and P215C compare against the output shaft.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine light on
• Speedometer dropping out
• ABS, traction or cruise control warnings, power dropouts

Common causes

• High Tyre size or speed factor not matching the vehicle (common after tyre or axle changes)
• Medium Faulty wheel speed sensor or damaged tone ring
• Medium Poor ABS module ground or wiring fault in the speed signal path
• Low Fault in the transmission-side vehicle speed source

Likelihood is a general estimate across vehicles; your make and model may differ.