What it means
The signals of the HV battery temperature sensors C and D do not correlate within the calibrated tolerance.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The HV battery control system compares temperature sensor C with sensor D to check that both readings make sense together. This code sets when their difference exceeds the calibrated tolerance, so the system may not be able to trust its view of pack temperature.
Common causes
Most likely first.
- Faulty battery temperature sensor C or D
- Damaged wiring or poor connection in a sensor circuit
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 with a hybrid-capable scan tool, then compare live sensor C and D temperatures with nearby pack readings.
- With the HV system safely powered down, inspect the C and D sensor connectors and accessible wiring for looseness, corrosion, damage, or rubbing.
- Check live data for a sensor C or D value that is implausible, fixed, or intermittently changing compared with pack conditions.
- Test both sensor circuits for opens, shorts, and high-resistance connections using the wiring diagram and manufacturer's procedure.
- If circuit checks pass, measure sensors C and D individually against the manufacturer's specification to identify a failed sensor.
Common fixes
- Secure or repair the sensor C or D connector if it is loose or damaged.
- Repair corroded, chafed, or broken wiring to sensor C or D.
- Replace the sensor C or D that fails its individual test.
- Clear the code and confirm the C/D readings correlate during the prescribed verification.
Can I keep driving?
The vehicle may limit propulsion or charging because it cannot confidently compare temperatures at sensors C and D. Avoid demanding acceleration or charging until checked, and stop safely if reduced power makes traffic driving unsafe.
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.