What it means
The ECM detects a circuit high 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 measures temperature at one location in the hybrid or EV battery pack and sends its signal to the battery control system. This code sets when the sensor C circuit reads above the expected electrical range, commonly because the signal is open or shorted toward battery voltage.
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
- Record freeze-frame data and compare sensor C live data with the other pack temperature readings for an implausibly high or fixed value.
- Inspect the sensor C connector and harness for a disconnected plug, damaged wire, corrosion, or pin damage.
- Use the wiring diagram to check for an open in the sensor circuit or a signal wire shorted to battery voltage.
- Test sensor C and circuit continuity according to the manufacturer's specification and procedure.
- If the sensor and harness pass, investigate battery control module input faults and related codes.
Common fixes
- Reconnect or repair a loose sensor C connector.
- Repair an open or shorted sensor C signal wire.
- Replace sensor C if it fails the manufacturer's test.
- Repair or replace the battery control module if confirmed faulty.
Can I keep driving?
Avoid fast charging and demanding driving because the vehicle may restrict battery power when it cannot trust sensor C's reading. If the warning is accompanied by reduced power or unusual battery heating, stop safely and arrange prompt diagnosis.
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.