P0516 — Battery Temperature Sensor Circuit Low

What does P0516 mean?

P0516 means the control module detects the battery-temperature sensor signal below the expected calibrated voltage range.

Is it safe to drive with P0516?

P0516 usually does not create an immediate driving emergency, but it can interfere with charging control, so it should be diagnosed before a long trip.

What commonly causes P0516?

Common P0516 causes include a defective sensor, a shorted signal wire, a bad connector, or a damaged sensor-reference or ground circuit.

How is P0516 diagnosed with an OBD scanner?

An ELM327 scanner can confirm P0516 and reveal the battery-temperature value, if supported, allowing an implausibly low reading to be compared with actual battery temperature.

The engine control module sets code P0516 when it detects a problem with the battery temperature sensor circuit — specifically, when the voltage signal stays lower than it should. In plain terms, this diagnostic trouble code tells you the PCM has seen a "circuit low" condition on the sensor responsible for monitoring battery temperature. The PCM relies on this reading to manage charging output, cooling fan operation, and in some vehicles, transmission behavior. When the data goes out of range, the module logs the fault and turns on the Check Engine Light.

"Circuit low" means the voltage on that particular wire is sitting near ground instead of the expected working range — typically somewhere between 0.5 and 4.5 volts depending on temperature. Several things can drag the signal down: a wire with damaged insulation shorted to metal, a sensor that has failed internally and is pulling the circuit to ground, a connector with corrosion or loose pins, or in rare cases a problem inside the control module itself. The module watches this signal continuously while you drive, and if the reading stays out of bounds for long enough across a couple of drive cycles, P0516 gets stored and the MIL activates.

One of the most useful pieces of data saved alongside P0516 is the freeze frame — a snapshot of engine rpm, load, coolant temperature, vehicle speed, and other sensor readings the moment the fault occurred. That snapshot tells you whether the problem showed up at idle, under acceleration, when cold, or when hot, and that context guides the rest of your diagnosis.

Symptoms of P0516

• Check Engine Light is illuminated on the dashboard
• In some vehicles, fuel economy drops slightly due to incorrect charging management
• The battery temperature-related system may operate erratically or stop functioning
• Depending on the vehicle, a limp-home or reduced-power mode may activate
• Other electrical systems that depend on battery temperature data may behave oddly
• The problem may come and go, especially if a wiring issue is the cause

Common Causes of P0516

• Signal wire shorted to ground — often from chafed insulation or a pinched harness
• Failed battery temperature sensor pulling the circuit low internally
• Corroded, loose, or damaged connector at the sensor or PCM
• Missing or interrupted supply voltage to the sensor circuit
• Open or shorted wiring somewhere in the harness
• Poor ground connection affecting the circuit reference
• Blown fuse feeding the battery temperature sensor circuit
• Faulty control module driver for that specific circuit (less common)

How to Diagnose P0516

1. Connect an OBD2 scanner and confirm P0516 is stored. Save the freeze frame data — this shows exactly what conditions were present when the module logged the fault and is your best starting point.
2. Look for related trouble codes. Sometimes a single wiring problem triggers multiple codes, and patterns reveal the root cause faster than guessing. Also check for any manufacturer TSBs (technical service bulletins) for your specific make and model — many known issues have published fixes or software updates.
3. Visually inspect the wiring harness and connectors tied to the battery temperature sensor. Look for damaged insulation, broken wires hidden under tape, corrosion buildup, or pins that are pushed out of the connector shell.
4. Check for proper voltage at the sensor connector first — confirm the circuit has power. Then measure resistance from the signal wire to ground; a reading near zero ohms points to a direct short to ground in the harness.
5. Probe the sensor connector itself: verify reference voltage, ground, and signal continuity at the component. Swap known-good sensor if readings look wrong and the wiring checks out.
6. Wiggle-test the harness while monitoring live data — any signal dropout or wild fluctuation reveals a broken wire or intermittent short that may not show up on a static multimeter reading.
7. Clear the code, complete a full drive cycle matching the conditions captured in the freeze frame, and verify P0516 does not return. If it comes back, the root cause is still present.

Repair Options and Costs

Tackle the inexpensive and likely causes before swapping expensive components:

• Wiring harness repair or connector replacement: $80–$250
• Battery temperature sensor replacement: $150–$500
• Control module diagnosis and repair: $300–$1,000

The final bill hinges entirely on what part of the circuit actually failed. Wiring and connector issues are far more common than a bad control module and cost a fraction of the price.

Total Repair Cost for P0516

Parts and labor for P0516 at an independent shop typically runs between $80 and $1,000. A proper diagnosis before you buy parts is the single best way to keep costs low — the most expensive scenario (module replacement) is rarely the right answer, and spending $30 on a multimeter check can save you hundreds in unnecessary parts.

Can You Drive with P0516?

For most vehicles, the car stays drivable when P0516 is active — you may notice slightly reduced performance or an auxiliary system behaving strangely, but no critical function is usually lost. Treat it as urgent if the vehicle stalls, fails to start, or if any brake or steering-related warnings appear alongside the Check Engine Light.

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