What it means
The ECM detects a circuit intermittent/erratic fault on the hybrid/ev battery temperature sensor c circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery temperature sensor C reports temperature at one location in the hybrid or EV battery pack, and its signal should change smoothly with pack conditions. This code sets when the sensor C signal is erratic or intermittently lost, often as a connector or wiring contact changes with vibration.
Common causes
Most likely first.
- Sensor connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
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
- Review freeze-frame data and scan-tool history, then monitor sensor C live data for sudden dropouts or spikes.
- Inspect the sensor C connector for incomplete seating, corrosion, loose pins, or harness strain.
- Check the sensor C wiring and ground reference for intermittent contact, following the vehicle wiring diagram.
- With the vehicle stationary and using safe, approved procedures, check whether gentle harness movement coincides with a sensor C reading interruption.
- If wiring and connections remain stable, test sensor C and the battery control module input to the manufacturer's specification.
Common fixes
- Fully seat and secure the sensor C connector.
- Clean or repair corroded or loose connector terminals.
- Repair chafed or strained sensor C wiring or its ground connection.
- Replace sensor C if its signal remains erratic with sound wiring.
Can I keep driving?
Keep trips short and avoid fast charging, hard acceleration, and heavy loads until the intermittent reading is repaired; the vehicle may unexpectedly limit power or charging. Stop safely if the warning is accompanied by reduced power or signs of battery overheating.
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.