P0C69

What it means

P0C69 is the SAE J2012 generic code for a fault in the generator position sensor circuit B. The generator is the motor/generator used in hybrid and electrified drive systems, and its position sensor (often a resolver or similar) tells the control unit the rotor angle and speed. The control unit set the code because the signal from sensor circuit B was missing, out of range, noisy or implausible compared with what it expected.

Symptoms

• Malfunction indicator lamp and/or hybrid system warning lamp on
• Reduced power or the vehicle entering a limp-home mode
• Engine will not start or stalls in a hybrid system that uses the generator for cranking
• Rough running, hesitation or jerky transitions between electric and engine drive
• Poor fuel economy or the engine running more than usual
• Vehicle will not enter ready mode

Possible causes

• Damaged, chafed or corroded wiring to the generator position sensor circuit B (open circuit, short or high resistance)likely
• Loose, corroded or water-contaminated connector at the generator or control unitlikely
• Faulty generator position sensor (resolver) or its internal windingpossible
• Electrical interference or a fault in the sensor's shielding or earth connectionpossible
• Sensor misalignment or mechanical damage after generator or transmission workpossible
• Fault in the hybrid or motor control unit that processes the sensor signalrare
• Outdated control unit software where the manufacturer has a known fix for this coderare

How to diagnose

1. Read all stored and pending codes with freeze frame data, noting any other hybrid, inverter or generator codes and the conditions when it set
2. Check for manufacturer bulletins and the correct procedure for the specific model and hybrid system, as sensor layout varies
3. Inspect the wiring harness and connectors between the generator and control unit for chafing, heat damage, fluid ingress, bent pins and corrosion
4. Observe the live generator position and speed data to see if it is missing, erratic or dropping out when the harness is moved
5. Following the manufacturer's high-voltage safety procedure, isolate the system and test the sensor circuit for continuity, shorts to earth or voltage, and winding resistance against specification
6. Check the sensor mounting and alignment, and look for signs of mechanical damage or contamination
7. Check the control unit's power and earth supplies and whether a software update is available for this code
8. Clear the code and road test to confirm whether it returns

How to fix

• Repair or replace damaged wiring and clean or replace faulty connectors, sealing them against moisture
• Replace the generator position sensor or generator assembly if testing shows it is out of specification
• Correct sensor mounting or alignment and carry out any relearn or calibration procedure the manufacturer requires
• Restore proper shielding and earth connections where interference is found
• Update the control unit software if a known fault applies, or replace the unit only after the circuit and sensor are proven good

Can I keep driving?

Nearby codes

• P0C68GenericGenerator Position Sensor Circuit A Intermittent/Erratic
• P0C6AGenericGenerator Position Sensor Circuit B Range/Performance