P0516 low

Battery Temperature Sensor Circuit Low

The P0516 code means the vehicle's onboard diagnostic system has detected: Battery Temperature Sensor Circuit Low. This is a low severity code.

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Keep driving?: Yes, but fix soon
DIY difficulty: moderate
Estimated cost: $50 - $200 (parts and labor)

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Common Symptoms

Check Engine Light on
Charging system voltage too high for conditions
Battery overcharging symptoms
Possible battery swelling

Probable Causes (Ranked by Likelihood)

Short to ground in battery temperature sensor wiring Very High
Failed battery temperature sensor (reads low/shorted) High
Water intrusion in sensor connector Moderate
Damaged wiring near battery acid or corrosion Moderate

Step-by-Step Diagnostic Procedure

Read battery temperature sensor value; an extremely low or hot reading when the battery is actually cool confirms the issue
Disconnect the sensor and check for a short to ground on the signal wire
Inspect sensor wiring for corrosion from battery acid exposure
Measure sensor resistance and compare to the temperature chart; a very low reading indicates an internal short

Frequently Asked Questions

What does circuit low mean for P0516?

Circuit low means the ECM is seeing voltage on the battery temperature sensor circuit that is below the expected minimum. This makes the ECM think the battery is very hot, causing it to increase charging voltage, which can overcharge the battery.

Can an overcharged battery be dangerous?

Yes. Overcharging a battery causes excessive gassing, electrolyte loss, and heat buildup. In severe cases, the battery can swell, crack, or leak acid. Lead-acid batteries can also produce hydrogen gas, which is explosive.

How do I know if my battery is being overcharged?

Signs of overcharging include the battery feeling hot to the touch, a strong sulfur or rotten egg smell near the battery, visible swelling of the battery case, or corroded battery terminals. Measure charging voltage; it should be 13.5-14.7V at normal temperature.