P0517 — Battery Temperature Sensor Circuit High

P0517 — Battery Temperature Sensor Circuit High. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, poor ground connection, open or shorted wiring in the circuit.

powertrain (engine/transmission)

Is it safe to drive?

Avoid extended cold-weather driving If the vehicle starts normally and charging voltage is stable, it can usually be driven to a repair shop. Do not continue driving if P0517 causes repeated no-starts, charging warnings, or an inability to maintain battery charge.

Typical symptoms

The check engine light or malfunction indicator may illuminate with P0517 stored in the powertrain controller.
The controller may interpret the high signal as an extremely cold battery and reduce the allowable alternator charging output.
Repeated no-start or slow-cranking conditions may occur during cold weather if the powertrain controller limits operation based on the false temperature reading.
Freeze-frame data may show P0517 under cold-start, low-voltage, or poor-charging conditions.
Some vehicles display no drivability symptom beyond the warning lamp, although the underlying P0517 circuit fault remains present.

Common causes

A corroded, loose, or damaged battery temperature sensor connector can leave the P0517 signal circuit open or intermittent.
High resistance or an open circuit in the battery temperature sensor signal wire can force the powertrain controller to detect an abnormally high input.
The battery temperature sensor itself may have failed internally and no longer changes resistance correctly with temperature.
A short to the sensor's five-volt reference or another high-potential circuit can produce the high circuit condition identified by P0517.
An open or high-resistance sensor ground can make the input voltage appear falsely high to the powertrain controller.
A defective powertrain controller input or internal pull-up circuit is possible after wiring and sensor faults have been ruled out.

How to diagnose with an OBD scanner

Read and preserve P0517 Connect an OBD-II scanner, such as an ELM327 adapter running AIScanAuto, and read stored, pending, and permanent codes. Save the freeze-frame data and note whether P0517 returns immediately or only under specific temperature conditions.
Inspect the sensor and harness Locate the battery temperature sensor on or near the battery, then inspect its connector and wiring for corrosion, backed-out pins, heat damage, pinching, or water intrusion. Repair damaged terminals and ensure the connector is fully seated.
Measure the high-input condition Using the vehicle's circuit specifications, back-probe the sensor and powertrain-controller pins. If the controller sees a high voltage while the sensor side is normal, test for an open or high-resistance wire. If both sides are high, continue checking the sensor, five-volt reference, and ground.
Test the sensor and ground Check sensor resistance or voltage at a specified temperature and compare it with the service-manual range. Verify continuity from the sensor ground pin to its designated ground point and confirm that the reference and ground voltages remain stable. Replace the sensor if its response is incorrect.
Repair, clear, and verify After repairing the wiring, connector, ground, or sensor, clear P0517 with the scanner. Start the vehicle, confirm the battery temperature value is plausible if live data is supported, verify charging voltage, and road-test while watching for a return of the code.

Approximate repair cost

A typical independent-shop estimate is USD 100-450 for P0517 diagnosis and repair, depending on whether the connector, wiring, ground, or sensor needs service. These figures are estimates and vary by region.

Common questions

Does P0517 mean the battery is physically too hot?

No. P0517 indicates that the battery temperature sensor circuit voltage is abnormally high; it does not by itself confirm that the battery has reached an excessive temperature.

Can I drive the vehicle with P0517 stored?

You may drive cautiously if the battery starts and charges normally, but P0517 can cause charging limits or cold-start problems and should be diagnosed before extended cold-weather use.

Will clearing P0517 with a scanner repair the fault?

No. Clearing P0517 only erases the stored code. The code will return if the high sensor signal, open wiring, bad ground, or defective sensor remains.

Should the battery be replaced when P0517 appears?

Usually not. P0517 concerns the temperature-sensor circuit, so test the sensor, connector, wiring, and grounds before replacing the battery or powertrain controller.

When your vehicle's engine control module detects that the voltage on the battery temperature sensor circuit has climbed above its normal operating range, it sets OBD2 code P0517. The phrase "circuit high" tells you the module is seeing a reading that sits close to battery voltage—essentially too high for a functioning sensor circuit. This typically means one of three things: the signal wire has shorted to a power source, the ground return path has broken, or the sensor itself has failed in a way that forces the circuit high.

The battery temperature sensor itself plays a supporting but important role in your vehicle's charging management. It feeds temperature data back to the engine control module, which uses that information to modulate alternator output. Keeping the battery in its optimal charge range extends battery life and ensures electrical systems receive stable voltage. When P0517 sets, the control module loses reliable temperature feedback from that sensor, which can lead to suboptimal charging behavior over time.

One important thing to understand about P0517: the check engine light won't activate from a single bad reading. The module needs to confirm the fault persists under specific driving conditions before it triggers the warning and stores the code. This is why the freeze frame data captured alongside P0517 is so valuable—it records engine load, RPM, coolant temperature, and vehicle speed at the exact moment the fault was detected. Use those readings to recreate the problem during diagnosis.

Symptoms of P0517

Check Engine Light illuminated and P0517 stored in the ECU
Intermittent or complete failure of systems relying on accurate battery temperature data
Higher than normal fuel consumption in some vehicles
Possible limp-home mode activation depending on the affected circuit
In rare cases, reduced charging system performance or battery drain

Common Causes of P0517

The most frequent reason P0517 appears is a signal wire that has shorted directly to battery positive voltage. A failed battery temperature sensor pulling the signal line high is the second most common culprit. Beyond those, an open ground return on the sensor circuit will create the same high-voltage reading the module interprets as a fault. Faulty control module output drivers, poor ground connections at the sensor body, and blown fuses feeding the circuit can all produce the same result. Wiring harness damage from heat, vibration, or animal intrusion occasionally introduces the short that triggers this code.

How to Diagnose P0517

Connect an OBD2 scanner and confirm P0517 is stored, then save the freeze frame data showing the exact conditions present when the fault occurred.
Pull any related diagnostic trouble codes—often a different code points to the root cause. Check manufacturer technical service bulletins for your specific make and model, as many P0xxx codes have documented factory fixes or software updates available through the manufacturer website or NHTSA database.
Perform a thorough visual inspection of the battery temperature sensor wiring harness and its connectors, looking for chafed insulation, corroded terminals, broken wires, or evidence of moisture intrusion.
With the sensor unplugged, measure signal voltage at the harness connector. A high reading confirms a short to power in the harness; if the voltage drops to normal reference range, the sensor itself has failed.
Verify proper reference voltage, ground continuity, and signal integrity at the component connector using a multimeter.
Perform a wiggle test on the harness while monitoring live data—the signal will drop out if a wire is broken or partially severed.
Clear the code, complete a full drive cycle that reproduces the freeze frame conditions, and verify P0517 does not return.

Repair Options for P0517

Diagnostic results determine which repair makes sense. If the wiring harness is damaged, repair or replacement typically runs $80–$250 depending on accessibility and the extent of the damage. When the battery temperature sensor itself is faulty, replacement including parts and labor generally costs $150–$500 depending on vehicle design and local labor rates. In the uncommon event the engine control module's driver circuit for the sensor has failed, module repair or replacement is the only option, with costs ranging from $300–$1,000.

Total Cost to Fix P0517

The actual repair expense for P0517 falls somewhere between $80 and $1,000 depending entirely on which component caused the fault. Most vehicles will see the issue resolved at the lower end of that spectrum—wiring repairs or sensor replacement handles the majority of cases. The most expensive scenario, a faulty control module, occurs far less frequently. An accurate diagnosis before purchasing parts is always the smart money move.

Can You Drive with P0517?

Most vehicles remain fully drivable when P0517 is active, though you may notice slightly reduced fuel economy or diminished performance from certain electrical systems. The battery temperature sensor isn't typically a safety-critical component, so widespread drivetrain failure is unlikely. However, if the car exhibits stalling, failure to start, or warnings in the brake or steering systems, treat the situation as urgent and have it diagnosed immediately.