P0C6F
Hybrid/EV Battery Temperature Sensor B/C 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
- 6F
- FaultThe specific fault in that area
What it means
P0C6F means the hybrid or EV battery control unit has found that the readings from two of the traction battery temperature sensors, referred to as sensor B and sensor C, do not agree when they should be similar. The control unit compares the two signals, and when the difference exceeds the allowed limit for too long, or one reading is implausible against the other, it sets the code. Which physical sensors are B and C, and where they sit in the pack, depends on the model and battery design.
Symptoms
- Hybrid system, EV system or general warning light on the dash
- Reduced power or limited electric assist or range
- Battery cooling fan running louder or more often than normal
- Reduced or restricted charging, or charging slower than usual
- Fluctuating or inaccurate battery charge level
- Car enters a limp or protective mode
Possible causes
- Faulty battery temperature sensor (reading drifted or stuck)likely
- Damaged wiring, poor connection or corrosion in the sensor circuit or pack harnesslikely
- Uneven pack temperature from a restricted or failed battery cooling fan, blocked intake duct or coolant circuit faultpossible
- Fault in the battery monitoring or control module's sensor inputpossible
- Degraded or failing battery module near one of the sensors causing a genuine local temperature differencepossible
- Sensor loose or incorrectly seated after previous battery workrare
How to diagnose
- Check that the high-voltage system is treated as live: only technicians trained in high-voltage safety should open or work on the traction battery or its connectors.
- Read all stored and pending codes and the freeze frame data, noting any other battery temperature, cooling fan or voltage codes.
- Check manufacturer information for the model to identify which sensors are B and C and where they are located.
- Compare live data for all battery temperature sensors with the car cold and after a drive, and look for one reading that is stuck, offset or erratic.
- Inspect the battery cooling fan, intake and exhaust ducts and filters for blockage, debris or damage, and check the fan operates correctly.
- Where the model has liquid cooling, check coolant level, circulation and any related cooling system faults.
- With the system safely isolated, inspect the sensor wiring and connectors for damage, corrosion or looseness, and test the sensor circuit resistance and continuity against specification.
- Check for any manufacturer service information relating to this code on the specific model before replacing parts.
How to fix
- Replace the faulty temperature sensor or sensor assembly as identified by testing.
- Repair or replace damaged wiring or connectors in the sensor circuit.
- Clear blocked cooling ducts or filters and repair or replace a faulty battery cooling fan or coolant component.
- Repair or replace the battery monitoring or control module if the fault is confirmed in the module.
- Repair or replace the affected battery module or pack section if a genuine cell or module fault is causing the temperature difference.
Can I keep driving?
The car can usually be driven for a short time, but expect reduced performance and fix it soon, as the battery may not be protected properly from overheating. If you see further warnings, heavy power loss, unusual smells or heat from the battery area, stop safely and get the car recovered.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.