The battery temp sensor is located under the front of the battery. It is used by the PCM (Powertrain Control Module) to do its Fuel/Air density calculations and control the injector dwell time. It can affect the running of the car. Unless you have a DRB (Diagnostic Readout Box) to see the actual temperature it is reading it is hard to prove it has caused your problem. I would suggest checking to see if the connector is unplugged or shorted.Remove the connector and check for rust. You can check the sensor contacts with an ohm meter and see if there is any resistance. If it is open, it has failed internally and will need replacing.
RG