P0C4F covers the second traction motor: its resolver offset learn finished, but the angle it produced lies outside what the controller will accept. GM applies the same two tests as for motor A, an absolute correction above 30 degrees or a change of over 10 degrees against the value kept from earlier learns, both checked at key-off with the rotor nearly still and more than 192 V available. The 2011 Volt sets it on one trip as Type A; the 2016 and 2019 Volt tables also say Type A but wait for five key-off cycles with the angle out of range. No bulletin for this code has been published. A large offset jump usually means something mechanical changed, so the check after a motor or sensor job matters most. P0C18 means motor B was never learned.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- Malfunction indicator lamp after shutdown cycles
- Reduced propulsion or motor B unavailable
- Unusual noise or shudder under electric drive
Most likely causes
- Motor B resolver stator fitted in a different position after a repair
- Learn disturbed by a moving rotor or unstable high voltage at key-off
- Damaged motor B resolver giving a shifted angle
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0C4F means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- C: Subsystem depends on the code range
- 4F: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0C4F?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0C4F?
The most common causes are: motor B resolver stator fitted in a different position after a repair; learn disturbed by a moving rotor or unstable high voltage at key-off; damaged motor B resolver giving a shifted angle.
Related codes
- P0C4EDrive Motor A Position Exceeded Learning Limit
- P0C18Drive Motor B Position Sensor Not Learned
- P0A45Drive Motor B Position Sensor Circuit
- P0A46Drive Motor B Position Sensor Circuit Range/Performance
Sources
- gsi.ext.gm.com: 11OBDG01 HYBRID Diagnostics
- gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
- gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.