What it means
The HV battery temperature sensor G reports a circuit high fault. Cell-group temperature monitoring impaired on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Temperature sensor G measures a cell-group area inside the high-voltage battery, and its signal circuit lets the battery control system monitor that temperature. P0C7F sets when the sensor G circuit voltage is higher than the module expects, commonly because the signal wire is shorted to battery voltage, the sensor circuit is open, or a connector has a poor contact.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Read freeze-frame data and battery-system codes to confirm the sensor G circuit-high fault and check whether other temperature channels are affected.
- Compare live sensor G temperature with nearby channels to see whether the reading is implausibly high or fixed.
- With high-voltage safety procedures followed and the pack unopened, inspect accessible sensor G wiring and connector pins for damage, an open connection, or signs of a short to power.
- Test the sensor G circuit for an open or short to voltage and check the sensor and connector using the manufacturer’s procedure.
- Compare circuit measurements with the manufacturer’s specification before replacing the sensor or control module.
Common fixes
- Reconnect or repair an open sensor G circuit connection.
- Repair a sensor G signal wire shorted to battery voltage.
- Replace sensor G if testing confirms it is open or otherwise faulty.
- Repair a corroded or damaged connector that is interrupting the sensor G circuit.
Can I keep driving?
Arrange prompt service and avoid charging or driving if power is limited or a battery warning appears; the system may restrict operation because sensor G temperature cannot be trusted. Do not probe or open high-voltage battery components yourself.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.