Battery Temperature Sensor Circuit Range/Performance
Diagnostic trouble code P0514 indicates that the powertrain control module (PCM) has detected an irrational or out-of-range signal from the battery temperature sensor. The computer sets this code when the sensor's temperature reading does not correlate with expected values based on ambient air and engine coolant temperatures.
While the vehicle will typically still drive, an incorrect battery temperature reading can cause the alternator to overcharge or undercharge the battery. This should be diagnosed soon to prevent premature battery failure or charging system damage.
Common symptoms
- Illuminated Check Engine Light (MIL)
- Illuminated battery or charging system warning light
- Premature battery failure or frequent need for replacement
- Signs of battery overcharging, such as venting, acid leaks, or a sulfur smell
- Slow engine cranking due to an undercharged battery
Likely causes
- Faulty battery temperature sensor
- Corroded or loose electrical connection at the sensor
- Damaged, chafed, or broken wiring in the sensor circuit
- Defective or failing 12-volt battery
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Visually inspect the battery temperature sensor, wiring, and connector.
Look for: Look for corrosion, broken wires, or a loose connection at the sensor, which is often located under or near the battery tray.
Connect a scan tool and monitor the live data for the battery temperature sensor.
Look for: Check if the temperature reading is stuck at an extreme value (like -40 or 300 degrees) or if it fails to change as the vehicle warms up.
Test the battery temperature sensor resistance using a multimeter.
Look for: Compare the measured ohms to the manufacturer's temperature-resistance chart; an open or shorted reading indicates a failed sensor.
Measure the reference voltage at the sensor connector with the ignition on.
Look for: You should typically see a 5-volt reference signal from the PCM; if it is missing, there is a wiring or PCM issue.
Test the ground circuit at the sensor connector.
Look for: Ensure there is continuity to ground; high resistance indicates a poor ground connection that can skew the sensor reading.
This page explains the generic P0514 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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