What it means
The battery temperature sensor reports a value within plausible range yet inconsistent with engine bay or coolant temperature. Modern alternator regulation uses battery temperature to adjust charging voltage, so an offset here causes over- or undercharging.
At a glance
- Usually lights the check-engine light
How it works
The battery temperature sensor provides battery temperature information used by the charging system to adjust its charging strategy. P0514 sets when the reported temperature is plausible on its own but does not agree with expected temperatures or charging-system conditions.
Common causes
Most likely first.
- Faulty battery temperature sensor
- Damaged or corroded sensor connector
- Open or shorted sensor wiring
- Sensor reading affected by poor battery sensor contact
Symptoms
- Check-engine or charging-system warning light on
- Battery may be undercharged or overcharged
- Unusual charging voltage or battery drain
How to diagnose it
- Check freeze-frame data and live battery temperature alongside ambient and engine coolant temperatures after the vehicle has sat long enough for them to be comparable.
- Inspect the battery temperature sensor, its contact with the battery or battery area, and its connector for poor fit, corrosion, or damage.
- Check the sensor wiring and terminals for opens, shorts, or poor contact, and verify circuit readings against the wiring diagram and manufacturer's specification.
- Compare the sensor reading with an independent temperature measurement at the sensor location to identify an offset.
- If the sensor placement and wiring are sound but the reading remains inconsistent, test or replace the sensor using the manufacturer's procedure.
Common fixes
- Restore proper sensor contact or mounting at the battery.
- Clean and secure a corroded or loose sensor connector.
- Repair damaged or high-resistance sensor wiring.
- Replace a battery temperature sensor that reads inaccurately despite sound wiring.
Can I keep driving?
Limit driving if the charging warning appears or the battery is not charging normally, since incorrect temperature information can lead to undercharging or overcharging. Switch off nonessential electrical loads and arrange prompt diagnosis if charging is abnormal.
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.