P0C6E
Hybrid/EV Battery Temperature Sensor A/B Correlation.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- C
- AreaHybrid propulsion
- 6E
- FaultThe specific fault in that area
What it means
P0C6E is the generic code for a correlation fault between Hybrid/EV battery temperature sensor A and sensor B. The control unit compares the readings from the two sensors, which would normally be close to each other for the conditions, and sets the code when they disagree by more than the calibrated limit or do not follow each other as expected. The exact sensor positions and the way the 'A' and 'B' sensors are defined vary by manufacturer and model.
Symptoms
- Hybrid system or battery warning light on the dashboard
- Malfunction indicator lamp on
- Reduced power or limited electric assist
- Cooling fan for the battery running loudly or constantly
- Reduced electric-only driving or poorer fuel economy
- Charging slower than usual or limited charging on plug-in or electric models
Possible causes
- Faulty battery temperature sensor A or B (reading drifted, stuck or implausible)likely
- Damaged wiring, corrosion or loose connector at the sensor or battery pack harnesslikely
- Restricted airflow or blocked intake or duct for the battery cooling system causing a genuine temperature difference between sensorspossible
- Faulty battery cooling fan, pump or coolant circuit fault (depending on model) causing uneven pack temperaturespossible
- Fault in the battery monitoring unit or battery control modulerare
- Outdated or faulty control unit software where the manufacturer has issued a known correctionrare
How to diagnose
- Read all stored and pending codes and the freeze frame data, noting battery temperatures, ambient temperature and vehicle state when the code set.
- Check for other related codes such as other battery temperature sensor, cooling fan or battery monitoring codes, and deal with those first.
- Using a suitable scan tool, compare the live readings of all battery temperature sensors after the car has sat cold for several hours; they should be very close to each other and to ambient.
- Watch the sensor readings while the system warms up or is under load and look for a sensor that is stuck, jumps or lags behind the others.
- Inspect the battery cooling air intake, ducts, filters and fan for blockage, debris or damage, following the manufacturer's procedure.
- Inspect the sensor wiring and connectors for damage, moisture and corrosion, and check for resistance, short or open circuit against the manufacturer's data. Follow high-voltage safety procedures and only work on the pack if trained and qualified.
- Check the cooling fan or coolant circuit operation (depending on model) for correct function and flow.
- Check for software updates or technical service bulletins for the specific model and fit any that apply.
How to fix
- Replace the faulty battery temperature sensor or sensor assembly, as directed by the manufacturer's procedure.
- Repair or replace damaged wiring and clean or replace corroded connectors.
- Clear blocked cooling ducts, intake or filters and refit any loose or damaged ducting.
- Repair or replace the battery cooling fan, pump or related parts if they are not working correctly.
- Repair or replace the battery monitoring unit or control module if testing proves it faulty.
- Apply a manufacturer software update if one is available for a known fault.
Can I keep driving?
The car may be driveable, often in a reduced-power mode, but the system cannot reliably monitor battery temperature, so get it checked soon. Stop driving and seek help if there is a high-voltage battery warning, burning smell, smoke or a rapid loss of power.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.