Damaged or corroded wiring harness at the generator position sensor connector; Failed generator position sensor A; Open or shorted sensor signal or ground circuit; Metal debris or contamination on the sensor pickup; Loose or improperly seated sensor mounting; Internal fault in the hybrid starter-generator assembly; Powertrain control module software or hardware issue

DTC codes / P0Cxx · Hybrid propulsion / P0C64

P0C64Generator Position Sensor Circuit A Circuit

Q: What does code P0C64 mean?

Generator Position Sensor Circuit A Circuit. P0C64 indicates that the powertrain control module has detected an abnormal condition in the circuit for Generator Position Sensor A, which is used to monitor the rotor position of the hybrid starter-generator. The code is set when the sensor signal voltage or circuit continuity falls outside the expected range during key-on or while the generator is spinning.

P0C64 indicates that the powertrain control module has detected an abnormal condition in the circuit for Generator Position Sensor A, which is used to monitor the rotor position of the hybrid starter-generator. The code is set when the sensor signal voltage or circuit continuity falls outside the expected range during key-on or while the generator is spinning.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or service vehicle soon message
Often no symptoms besides the warning light
Reduced or absent charging from the hybrid generator, leading to a low 12-volt battery
Inability of the engine to restart smoothly after an auto-stop event
Rough running or stalling when the generator is commanded to assist the engine
A warning message indicating a hybrid system fault or reduced power

Common causes, most likely first

Damaged or corroded wiring harness at the generator position sensor connector
Failed generator position sensor A
Open or shorted sensor signal or ground circuit
Metal debris or contamination on the sensor pickup
Loose or improperly seated sensor mounting
Internal fault in the hybrid starter-generator assembly
Powertrain control module software or hardware issue

How to diagnose and fix it

Inspect the sensor connector and wiring for corrosion, chafing, or loose pins
Measure sensor resistance and compare to the manufacturer's specification
Check the signal voltage at the sensor with a multimeter while cranking or spinning the generator
Verify the sensor ground circuit for continuity to the chassis
Clean the sensor tip and mounting surface of any metallic debris
Replace the generator position sensor if electrical tests fail
Reprogram or replace the powertrain control module only after all other tests pass

When the sensor is not the real culprit

A loose or corroded ground connection at the generator housing can mimic a failed position sensor and set P0C64 without any sensor fault.
Metallic debris from a failing generator bearing can accumulate on the sensor tip and disrupt the signal, so always inspect the sensor and housing for metal shavings.
The code can be set by a momentary loss of signal during engine start, so check for intermittent connector issues before condemning the sensor.
A weak 12-volt battery can cause erratic sensor signals and set this code, so load-test the battery and charging system first.
After replacing the sensor, some vehicles require a relearn procedure for the generator position, which a scan tool must perform.

Can I keep driving with P0C64?

You can drive the vehicle short distances to a repair shop, but avoid relying on the hybrid system for assistance and do not take long trips. Continued driving may discharge the 12-volt battery and cause stalling or a no-start condition.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.