P0C57 code meaning
Drive Motor B Position Sensor Circuit A Low
Powertrain system Generic code P0Cxx codes Check engine light
What P0C57 means
P0C57 means the reference level on Circuit A of the motor B resolver, the S1/S3 winding in GM wiring, has sunk below its limit. GM checks it exactly like the motor A line: under 0.5 V on the 2011 and 2016 Volt and the 2012 two-mode trucks, under 0.10 V on the 2019 Volt, with Type A on the early cars and Type B from 2016. In the field it rarely stands alone. GM preliminary information PIC5856A to F for 2011-13 Volt and 2014-16 ELR groups P0C57 with P0C58 and P0C62: if wiring checks and normal diagnosis find nothing, the motor B position sensor is replaced and the drive motor generator control module is brought to its latest calibration. A genuine harness fault to ground still has to be excluded before any parts are ordered.
P0C57 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0C57
- Service engine soon lamp, current or in history
- Often stored together with P0C58 and P0C62
- Reduced propulsion
Common causes of P0C57
- Most likelyFaulty motor B position sensor (resolver stator) on Volt and ELR (GM PIC5856)
- PossibleCircuit A line of motor B shorted to ground in the harness
- Less likelyDrive motor generator control module not on the latest calibration
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor b position sensor aWiring harnessHybrid control module
What each part of P0C57 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| C | Area: hybrid propulsion. |
| 57 | The exact fault in that area. |
What to do next
- Note P0C57 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0C57
What does P0C57 mean?
P0C57 means "Drive Motor B Position Sensor Circuit A Low". P0C57 means the reference level on Circuit A of the motor B resolver, the S1/S3 winding in GM wiring, has sunk below its limit. It is a generic code, so it means the same on every make.
Is it safe to drive with P0C57?
Drive gently and only to a workshop. With P0C57 the car can go into limp mode (reduced power) to protect itself.
Will P0C57 fail an emissions test?
Yes, it can. P0C57 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0C57 to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P0C57 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.