What it means
The control module detects that the hybrid/EV battery temperature sensor A signal is outside the expected range or does not match expected performance.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery temperature sensor A reports temperature at one monitored location in the hybrid or EV battery pack. This code sets when its signal is electrically plausible but falls outside the expected range or does not behave as expected compared with operating conditions or other temperature readings.
Common causes
Most likely first.
- Temperature sensor fault
- Wiring or connector fault
- Sensor installation or contact problem
Symptoms
- Hybrid system warning light
How to diagnose it
- Record freeze-frame data and compare sensor A's reading with other battery temperature sensors and ambient conditions.
- Check live data as the vehicle warms or cools to see whether sensor A changes smoothly and consistently.
- Inspect the accessible sensor A connector, wiring, and mounting for damage, poor contact, or a sensor that is not seated as intended.
- Check the sensor circuit and sensor response using the manufacturer's test procedure and specification.
- If sensor A and its circuit pass, investigate the control module's interpretation or related battery temperature data using the manufacturer's diagnostic procedure.
Common fixes
- Correct sensor A's seating or contact issue if accessible and specified by the manufacturer.
- Repair damaged wiring or a poor sensor A connector contact.
- Replace sensor A if its response is outside the manufacturer's specification.
- Repair a confirmed control-module or related circuit fault.
Can I keep driving?
Arrange a prompt check because an implausible sensor A reading can cause the vehicle to restrict battery use or cooling decisions. Avoid strenuous driving if a hybrid warning or reduced power appears, and do not open the high-voltage battery pack.
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.