P0515: Battery Temperature Sensor Circuit

What it means

A general circuit fault is detected on the battery temperature sensor - open or short on supply, signal or ground.

At a glance

• Usually lights the check-engine light

How it works

The battery temperature sensor sends a temperature signal to the charging control system so it can account for battery temperature. P0515 sets when the control module detects a general electrical fault in the sensor circuit, such as an open or short.

Common causes

Most likely first.

1. Faulty battery temperature sensor
2. Open or shorted sensor wiring
3. Loose, corroded, or damaged connector
4. Blown fuse or loss of power or ground

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

1. Check freeze-frame data and live battery temperature for a fixed, missing, or implausible reading associated with the circuit fault.
2. Inspect the battery temperature sensor and connector for looseness, corrosion, moisture, or damaged terminals.
3. Check the relevant fuse and verify sensor circuit power and ground against the wiring diagram and manufacturer's specification.
4. Test the signal and supply wiring for opens or shorts to ground or power, including the harness near the battery.
5. If the wiring and connections are sound, test the sensor according to the manufacturer's procedure and replace it if it fails.

Common fixes

• Secure or clean the battery temperature sensor connector.
• Repair an open or shorted sensor wire.
• Restore a failed fuse, power feed, or ground after identifying the cause.
• Replace the battery temperature sensor if its circuit response fails testing.

Can I keep driving?

If the charging warning is on or charging voltage appears abnormal, limit driving because the battery may be undercharged or overcharged. Reduce nonessential electrical loads and arrange diagnosis promptly.