Complaint: The customer states the check engine light is on.
Cause: A scan tool finds code P0517 – Battery Temperature Sensor Circuit High. A road test, while using the scan tool to monitor live data, finds the battery temperature sensor signal parameter is above specifications. A visual inspection of the battery temperature sensor wiring harness shows no obvious signs of damage.
With the key on and engine off, the battery temperature sensor connector was disconnected, and the battery temperature parameter dropped below the allowable range. Then, a fused jumper wire was connected across the terminals at the battery temperature sensor connector, which caused the battery temperature parameter to increase.
Using a multi-meter, the resistance of the battery temperature sensor was measured, and found the sensor was internally shorted. The results of these tests verified the battery temperature sensor was faulty.
Correction: Replaced the battery temperature sensor, cleared codes, performed a road test and verified the vehicle operated properly. The check engine light did not illuminate and no fault codes returned.
Courtesy of Mitchell 1’s SureTrack Real Fixes. For more, visit mitchell1.com.