P0515
Battery Temperature Sensor Circuit
- Severity
- Medium
- Driving
- Drivable — book it in
A fault in the battery temperature sensor circuit. Charging voltage is temperature-compensated on most modern vehicles - a cold battery needs a higher charging voltage than a hot one. Without a believable temperature the module has to guess, and a wrong guess means the battery is systematically over- or under-charged.
Possible causes
- CommonFailed battery temperature sensor
- CommonCorroded connector at the sensor
- CommonWiring damage - the sensor often sits under or beside the battery
- PossibleAcid damage to the sensor or its wiring from a leaking battery
- PossibleSensor not refitted after battery replacement
- PossibleLoss of reference voltage or earth
What you might notice
- Battery warning light on
- Charging voltage slightly wrong
- Battery life shorter than expected
- Check engine light on
- Often no symptom the driver notices
What to check, in order
- Ask whether the battery has been replaced recently. The sensor is easily left disconnected or not refitted during a battery change, and that is a very common cause.
- Compare the reported battery temperature with ambient on a vehicle that has stood overnight - they should be close.
- Inspect the sensor and its wiring for acid damage. A battery that has leaked destroys everything near it.
- Check the connector for corrosion.
- Check charging voltage against specification while you are there, since this fault affects it directly.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Vehicle speed control, idle control and auxiliary inputs
P0500P0501P0502P0503P0504P0505P0506P0507P0508P0509P0510P0511P0512P0513P0514P0515P0516P0517P0518P0519P0520P0521P0522P0523P0524P0525P0526P0527P0528P0529P0530P0531P0532P0533P0534P0535P0536P0537P0538P0539P0540P0541P0542P0543P0544P0545P0546P0547P0548P0549P0550P0551P0552P0553P0554P0555P0556P0557P0558P0559P0560P0561P0562P0563P0564P0565P0566P0567P0568P0569P0570P0571P0572P0573P0574P0575P0576P0577P0578P0579P0580P0581P0582P0583P0584P0585P0586P0587P0588P0589P0590P0591P0592P0593P0594P0595P0596P0597P0598P0599