Code P0517 indicates that the powertrain control module (PCM) is detecting a voltage signal from the battery temperature sensor that is higher than the normal operating range. This typically points to an open circuit in the wiring or a failed sensor. The PCM uses this temperature data to adjust alternator charging voltage based on battery conditions.
The internal thermistor inside the sensor can fail or go open, causing the voltage signal to spike out of range.
Chafed, broken, or disconnected wires between the sensor and the PCM will cause a high-voltage open circuit condition.
Corrosion on the battery terminals or the sensor plug can interrupt the signal, leading to an abnormally high reading.
Acid leaking from the battery onto the sensor or its wiring can degrade the electrical connections and damage the component.
A rare internal failure in the powertrain control module could misinterpret the sensor voltage, but this is highly uncommon.
You can usually drive the vehicle, but the charging system may not operate correctly. If the PCM assumes the battery is very cold, it may overcharge the battery, leading to premature failure.
It is typically mounted to the battery tray, located directly beneath the battery, or integrated into the battery positive cable clamp.
No, replacing the PCM is almost always the wrong fix for P0517. The problem is nearly always a failed temperature sensor or damaged wiring in the circuit.
Not necessarily, unless the battery is leaking acid that damaged the sensor. The sensor and wiring can often be repaired or replaced independently of the battery.