P0515 — Battery Temperature Sensor Circuit

What does OBD2 code P0515 mean?

P0515 identifies a fault in the circuit that reports battery temperature to the vehicle's control module, commonly involving the sensor, wiring, connector, or related input.

Can the vehicle be driven with P0515 active?

Driving may be possible, but incorrect temperature input can affect charging or battery thermal management. Diagnosis should be scheduled promptly, especially if battery or high-voltage warnings are present.

What are the most common causes of P0515?

Common causes include a failed battery temperature sensor, an open or shorted signal wire, corroded connector terminals, damaged harness insulation, or a faulty module reference or ground.

How is a P0515 battery temperature sensor circuit diagnosed?

A technician confirms the code with an OBD scanner, inspects the sensor and wiring, and tests reference voltage, ground, signal voltage, and sensor resistance against the service specifications.

The engine control module (ECM) logs trouble code P0515 when it detects a problem in the battery temperature sensor circuit. This is a powertrain-related OBD2 code that specifically points to a fault between the sensor itself and the module's ability to read its signal. The battery temperature sensor helps the vehicle's computer monitor thermal conditions in the battery pack, which influences charging rates, cooling fan operation, and other related systems.

Setting P0515 isn't a one-time glitch. The ECM requires the fault condition to appear consistently under specific operating parameters before it triggers the Check Engine light and stores the code. When the module logs this code, it also captures freeze frame data — a snapshot showing engine load, RPM, coolant temperature, and vehicle speed at the exact moment the problem occurred. That snapshot is your roadmap for reproduction during diagnosis.

The real value of understanding P0515 lies in recognizing that the battery temperature circuit serves important functions. When the sensor fails or the signal path breaks down, the ECM may revert to default strategies, potentially affecting fuel economy, charging behavior, or auxiliary system performance. Pinpointing whether the fault lives in the wiring, the connector, or the sensor itself determines the repair path and cost.

Common Symptoms of P0515

• The Check Engine Light illuminates on the dashboard
• The affected circuit operates intermittently or stops working entirely
• Some vehicles experience decreased fuel efficiency due to incorrect charging management
• Depending on which component is affected, the car may enter reduced-power limp mode
• Cooling fans may behave erratically or not activate when they should
• In rare cases, battery charging irregularities occur during extended driving

What Causes P0515?

• An open or shorted wire somewhere in the battery temperature sensor circuit
• A corroded, loose, or physically damaged connector interrupting the signal path
• The battery temperature sensor itself has failed internally
• A blown fuse that feeds power to the circuit
• A poor ground connection preventing proper signal return
• The ECM has an internal driver fault affecting that specific input channel

How to Diagnose P0515

1. Connect an OBD2 scanner and confirm P0515 is currently stored. Save the associated freeze frame data — it records the exact conditions when the module first detected the fault.
2. Review any other trouble codes present. Related codes often point toward the root cause, whether it's a power issue, ground problem, or communication fault. Also check manufacturer TSBs for your specific make and model — many P0xxx codes have documented factory fixes or software updates.
3. Perform a visual inspection of the wiring harness and connectors tied to the battery temperature sensor circuit. Look for frayed insulation, corrosion buildup, pinched wires, or any signs of heat damage.
4. At the sensor connector, measure reference voltage, ground integrity, and signal continuity. Compare your readings against factory specifications for the circuit.
5. Conduct a wiggle test on the harness while monitoring live data. Any signal dropouts or interruptions during movement indicate a broken wire inside the insulation.
6. Clear the code, then drive the vehicle through a complete drive cycle that recreates the conditions shown in the freeze frame data. Verify that P0515 does not reappear.

Repair Options for P0515

Address the most likely and least expensive culprits before replacing major components:

• Wiring or connector repair: $80–$250. Cleaning corrosion, repairing broken wires, or replacing damaged connectors often resolves the issue without further intervention.
• Sensor or actuator replacement: $150–$500. If testing confirms the battery temperature sensor itself has failed, replacement restores proper circuit operation.
• Control module repair: $300–$1,000. In rare cases where the ECM's internal driver for that circuit has failed, module repair or replacement becomes necessary.

How Much Does It Cost to Fix P0515?

Total repair costs hinge on which component is actually responsible. Based on typical parts and labor rates at independent shops in the United States:

• Wiring or connector work typically falls between $80 and $250.
• Sensor or actuator replacement generally runs $150 to $500.
• Control module service or replacement ranges from $300 to $1,000.

Across all scenarios, fixing P0515 usually costs somewhere between $80 and $1,000. A methodical diagnosis before purchasing parts pays for itself — the priciest fix is rarely the first place to look.

Can You Drive with P0515?

In most instances, the vehicle remains drivable, though you may notice reduced performance or a disabled auxiliary system depending on which circuit is affected. However, if the car exhibits stalling, fails to start, or triggers brake and steering warnings, treat the situation as urgent and have it assessed immediately.

Related OBD2 Codes

• P0500: Vehicle Speed Sensor "A" Malfunction
• P0501: Vehicle Speed Sensor "A" Range/Performance
• P0502: Vehicle Speed Sensor "A" Low Input
• P0503: Vehicle Speed Sensor "A" Intermittent/Erratic/High
• P0504: Brake Switch "A"/"B" Correlation
• P0505: Idle Control System Malfunction