P0C17Drive Motor A Position Sensor Not Learned
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0C17 means the controller has no valid learned offset for the resolver of motor A, which it needs to align rotor position with the stator field. GM runs the learn at key-off and sets the code if it fails without a stored value: motor speed above 50 rpm, DC voltage below 192 V (200 V on the 2016 Volt), phase current below 15 A or a learn time over 1.4 s. The Volt is Type A, the 2012 two-mode trucks Type B. GM bulletin 21-NA-218 links it to missing high voltage or three-phase current, loose phase terminals or stator damage on Volt and ELR. Mazda requires the speed sensor learn on CX-90 and CX-70 PHEV after inverter or motor replacement. P0C4E reports a learned value out of range.
- What you may notice
- Engine starts and stalls or will not start after a repair
- Malfunction indicator lamp with reduced propulsion message
- Electric drive unavailable
- Likely causes
- LikelyOffset learn not performed after replacing the inverter, motor or resolver
- PossibleHigh voltage not reaching the inverter during the learn, e.g. contactor or HV cable fault
- PossibleLoose three-phase ring terminals after a repair
- RareDamaged motor stator winding (GM 21-NA-218)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €80 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.