P0C7E

What it means

P0C7E means the hybrid or EV control unit has detected the signal from traction battery temperature sensor 'G' sitting below its expected electrical range. This usually points to a short to ground or a failed sensor rather than a genuinely cold battery. The unit cannot trust the temperature reading, so it sets the code and may limit battery use.

Symptoms

• Hybrid or EV system warning light on the dashboard
• Reduced power or limp-mode behaviour
• Reduced electric-only driving or regeneration
• Battery cooling fan running constantly or not at all
• Reduced charging rate or charging refused on plug-in or electric models
• Reduced fuel economy on hybrids

Possible causes

• Faulty traction battery temperature sensor G reading out of range lowlikely
• Sensor signal wire shorted to ground, for example from chafed or pinched insulationlikely
• Damaged, corroded or contaminated connector or terminals at the sensor or battery control unitpossible
• Water ingress or coolant leak affecting the sensor circuit inside the battery pack areapossible
• Fault within the battery control unit or its sensor input circuitrare
• Previous pack repair or service leaving a harness trapped or incorrectly refittedrare

How to diagnose

1. Read all stored and pending codes and freeze frame data, noting whether other battery temperature sensor codes are also present.
2. Check for technical service bulletins or software updates for the model, as the location of sensor G depends on the vehicle.
3. View live data for all battery temperature sensors and compare sensor G with the others when the pack is at rest and cold; a reading stuck very low or at the limit suggests a circuit fault.
4. Inspect accessible wiring and connectors for damage, moisture, corrosion and bent or pushed-back pins.
5. Following the manufacturer's high-voltage safety procedure and only if trained, isolate the system and check the sensor circuit for short to ground, continuity and sensor resistance against specification.
6. Check the sensor reference voltage and signal at the control unit connector as per the wiring diagram for that model.
7. Clear the code and road test or cycle the system, rechecking live data to confirm the fault does not return.

How to fix

• Replace the faulty temperature sensor or sensor assembly in line with the manufacturer's procedure.
• Repair or replace damaged wiring where it is shorted to ground, using approved methods.
• Clean, repair or replace affected connectors and terminals.
• Fix the source of any water or coolant ingress and dry or replace the affected components.
• Update or reflash the control unit software only if a bulletin lists it as a fix, or replace the control unit if confirmed faulty.

Can I keep driving?

Nearby codes

• P0C7DGenericHybrid/EV Battery Temperature Sensor G Circuit Range/Performance
• P0C7FGenericHybrid/EV Battery Temperature Sensor G Circuit High