RAM 2500 Truck 2WD V8-5.7L (2008)
Battery Temperature Sensor: Description and Operation
Battery Temperature Sensor - Operation
OPERATION
The BTS is used to determine the battery temperature and control battery charging rate. This temperature data, along with data from monitored line
voltage, is used by the PCM (ECM Diesel) to vary the battery charging rate. System voltage will be higher at colder temperatures and is gradually
reduced at warmer temperatures.
The PCM sends 5 volts to the sensor and is grounded through the sensor return line. As temperature increases, resistance in the sensor decreases and the
detection voltage at the PCM increases.
The BTS is also used for OBD II diagnostics. Certain faults and OBD II monitors are either enabled or disabled, depending upon BTS input (for
example, disable purge and enable Leak Detection Pump (LDP) and O2 sensor heater tests). Most OBD II monitors are disabled below 20°F.
