What it means
The hybrid/EV battery pack coolant temperature sensor D reading is outside the expected range or does not respond as expected. The reading may be unreliable.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The BMS monitors the reading from hybrid/EV battery pack coolant temperature sensor D and checks whether it stays within a plausible range and responds as expected. This code sets when sensor D's reading is out of range or behaves implausibly, which can result from sensor drift, poor mounting, or an aged sensor element.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
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 graph sensor D live temperature from startup through warm-up to see whether it is plausible and changes smoothly.
- Compare sensor D with other battery coolant temperature sensors and ambient conditions to identify an isolated offset or a reading that does not respond.
- With the vehicle made safe under the manufacturer's procedure, inspect sensor D mounting and its connector and harness for displacement, damage, moisture, or corrosion.
- Check the battery cooling system for visible coolant loss or restricted flow that could explain unusual temperature behavior.
- Test sensor D response and circuit condition against the manufacturer's specifications before replacing the sensor or suspecting BMS calibration.
Common fixes
- Secure sensor D in its specified mounting position if it has shifted.
- Repair damaged or corroded sensor D wiring and connector contacts.
- Replace sensor D if its temperature response remains outside the manufacturer's specification.
- Repair a confirmed battery cooling system fault and perform any required BMS calibration.
Can I keep driving?
The BMS may restrict power or charging if sensor D gives an implausible battery coolant temperature. Avoid fast charging and heavy loads until diagnosed, and stop driving if an overheating or battery cooling warning appears.
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.