Battery Temperature Sensor Circuit High
The ECU detected that the battery temperature sensor is sending a signal that's too high, indicating an unusually hot battery. It's like a thermometer reading that's stuck at the maximum temperature.
The ECM monitors voltage from the battery temperature sensor to estimate battery temperature for optimal charging control. The sensor uses a thermistor that changes resistance based on temperature. When the ECU reads a voltage above the high threshold, it sets this fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Sensor Voltage | 0.5V - 4.5V (approximately -40°C to 125°C) | Above 4.7V or signal stuck high |
| Battery Temperature Signal | -40°C to 125°C | Reading above upper limit (>130°C equivalent) |
Code P0517 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0517 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.