Battery Temperature Sensor Circuit High
The P0517 code indicates that the Powertrain Control Module (PCM) has detected a voltage signal from the battery temperature sensor circuit that is higher than the manufacturer's specified maximum limit. This typically signifies an open circuit or a sensor that is falsely reporting an extremely low battery temperature.
While the vehicle will usually remain drivable, an inaccurate battery temperature reading can cause the alternator to charge the battery incorrectly. This can lead to premature battery degradation or a dead battery if left unaddressed.
Common symptoms
- Illuminated Check Engine Light
- Battery warning light illuminated on the dashboard
- Battery charging system issues (overcharging or undercharging)
- Reduced battery life or premature battery failure
- Engine may fail to start if the battery becomes depleted
Likely causes
- Faulty battery temperature sensor
- Open circuit or high resistance in the battery temperature sensor wiring
- Corroded, loose, or damaged electrical connector at the sensor
- Damaged battery tray (where the sensor is often mounted)
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Visually inspect the battery temperature sensor and its wiring harness.
Look for: Look for broken wires, melted insulation, or severe corrosion at the sensor connector, which is typically located under or near the battery tray.
Disconnect the sensor and check the connector for corrosion or bent pins.
Look for: Green or white powdery corrosion, moisture, or damaged pins that would cause high resistance or an open circuit.
Measure the resistance of the battery temperature sensor using a digital multimeter.
Look for: Compare the resistance reading to the manufacturer's temperature-to-resistance chart; an infinite reading (OL) indicates an internal open circuit requiring sensor replacement.
Check the reference voltage and ground at the sensor connector with the ignition on.
Look for: A steady 5-volt reference signal from the PCM and a good ground; absence of either indicates a wiring issue between the sensor and the PCM.
Test the continuity of the signal and ground wires between the sensor connector and the PCM.
Look for: High resistance or no continuity (OL) indicates a broken wire in the harness that needs to be repaired.
This page explains the generic P0517 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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