P0515 low

Battery Temperature Sensor Circuit High

The P0515 code means the vehicle's onboard diagnostic system has detected: Battery Temperature Sensor Circuit High. 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 low for conditions
Battery may not fully charge
Start/stop system disabled

Probable Causes (Ranked by Likelihood)

Open circuit in battery temperature sensor wiring Very High
Failed battery temperature sensor (reads high) High
Corroded battery terminal affecting sensor signal Moderate
Sensor disconnected from battery Moderate

Step-by-Step Diagnostic Procedure

Check battery temperature sensor reading with a scan tool; an extremely high reading confirms the circuit issue
Inspect the sensor connector and wiring for open circuits or corrosion
Verify sensor is properly mounted and in contact with the battery surface
Measure sensor resistance at the connector and compare to temperature chart in service manual

Frequently Asked Questions

What does circuit high mean for battery temperature?

Circuit high for a battery temperature sensor typically means an open circuit, which the ECM reads as extremely high resistance. The ECM interprets this as very cold battery temperature and may reduce charging voltage when it should not.

Can this code disable the start/stop system?

Yes. Many vehicles with automatic start/stop systems require accurate battery temperature data to determine if the battery can handle repeated restarts. If the sensor reports incorrect data, the system is disabled as a precaution.

Is P0515 related to alternator problems?

Not directly. P0515 is a sensor circuit issue, not an alternator problem. However, the incorrect temperature data can cause the ECM to command improper alternator output, which may appear as a charging problem.