Damaged wiring, chafed insulation or short or open circuit in the generator position sensor harness; Corroded, loose or contaminated connector at the sensor or the inverter or control unit; Faulty generator position sensor (resolver or equivalent); Sensor mounting or rotor position misaligned, or mechanical damage within the generator; Electrical interference or a fault in the supply or reference voltage to the sensor; Fault within the inverter or hybrid control unit; Outdated control unit software where the manufacturer has issued a fix.

P0C64

Generator Position Sensor Circuit A.

Generic
Powertrain
Generic code
High severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
C: AreaHybrid propulsion
64: FaultThe specific fault in that area

What it means

P0C64 is a generic powertrain code relating to the generator position sensor, circuit A. This sensor reports the rotor position of the generator (the motor-generator in a hybrid or electric drive system) to the control unit so it can time the current to the motor windings correctly. The code sets when the control unit sees a signal from that circuit that is missing, out of range or implausible. The exact sub-fault (open circuit, short, range or performance) and the wording vary by manufacturer.

Symptoms

Hybrid system or powertrain warning light on
Reduced power or the car going into limp mode
Engine will not start or the hybrid system will not go to Ready
Rough running, vibration or juddering when the engine starts or stops
Poor or erratic hybrid battery charging
Hybrid system shutting down while driving

Possible causes

Damaged wiring, chafed insulation or short or open circuit in the generator position sensor harnesslikely
Corroded, loose or contaminated connector at the sensor or the inverter or control unitlikely
Faulty generator position sensor (resolver or equivalent)possible
Sensor mounting or rotor position misaligned, or mechanical damage within the generatorpossible
Electrical interference or a fault in the supply or reference voltage to the sensorpossible
Fault within the inverter or hybrid control unitrare
Outdated control unit software where the manufacturer has issued a fixrare

How to diagnose

Read all stored and pending codes and note any related hybrid, inverter or motor codes
Review freeze frame data to see the conditions when the code set, and whether it returns after clearing
Visually inspect the sensor harness and connectors for chafing, heat damage, water ingress, corrosion and bent or pushed-back pins
Check for relevant technical service bulletins and software updates for the specific model and engine
Check the live data for the generator position or speed signal and see if it is missing, erratic or implausible
Test the sensor circuit wiring for continuity, short to earth and short to supply against the manufacturer's wiring diagram, with the high-voltage system isolated following the correct safety procedure
Measure the sensor coil resistance and compare it with the manufacturer's specification, which depends on the model
Check the generator's mounting and condition for mechanical damage or play, following the manufacturer's procedure

How to fix

Repair or replace damaged wiring and ensure it is routed and secured properly
Clean, repair or replace faulty connectors and terminals
Replace the generator position sensor, or the generator assembly if the sensor is not serviced separately
Correct sensor alignment or repair mechanical damage as specified by the manufacturer
Update the control unit software only if a bulletin identifies it as the cause
Repair or replace the inverter or control unit if testing confirms an internal fault

Can I keep driving?

High severity

Avoid driving if the car is in limp mode, has lost power or the hybrid system is shutting down, as it may stall or fail to restart. Have it inspected promptly by someone qualified to work on high-voltage systems.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.