What it means
The control module detects a range or performance fault in the hybrid battery pack air temperature sensor A circuit.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery-pack air temperature sensor A measures air temperature near the hybrid or EV battery, and the control module uses it when managing battery operation and cooling. This code sets when sensor A’s reading is electrically plausible but falls outside the expected range or does not respond as expected compared with operating conditions or other temperature readings.
Common causes
Most likely first.
- Air 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 reported temperature with ambient temperature, battery conditions, and sensor B if available.
- Check sensor A’s placement and seating according to the vehicle’s service information; a sensor that is displaced or poorly exposed to the pack air can report an unrepresentative temperature.
- Inspect sensor A’s connector and wiring for corrosion, loose pins, damage, or routing that could affect the reading.
- Watch sensor A’s live data as the battery warms or cools and check whether it responds smoothly and plausibly.
- Test sensor A and its circuit against the manufacturer’s specifications to determine whether the sensor, its installation, or the wiring is causing the range/performance fault.
Common fixes
- Correct sensor A’s position or seating if it is not installed as specified.
- Reseat the connector and clean or repair poor contacts in sensor A’s circuit.
- Repair damaged wiring or a poor connection affecting sensor A’s reading.
- Replace sensor A if its response fails the manufacturer’s tests.
Can I keep driving?
The hybrid system may restrict power or battery cooling if it cannot rely on sensor A’s temperature reading. Keep driving gentle and brief, and stop if a hybrid warning is joined by overheating or a substantial loss of power.
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.