DTC P0A9B (67): Battery Module Temperature Signal Circuit Problem: General Description

The battery module temperature sensor is used for various controls in the IMA (integrated motor assist) system. If the sensor output voltage is out of its normal range, exhaust emissions, fuel economy, or drivability may be adversely affected, and a malfunction in the sensor is detected and the MIL comes on. The battery temperature is measured by the thermistor that is attached to four of the 20 modules in the battery module. By using this temperature sensor, the maximum and minimum temperature in the battery module can be measured to within ±1.8°F (±1°C). Monitoring is done through the upper and lower limit of output voltage from four channels in the sensor.

If the voltage is higher than the upper threshold, an open is detected, and if it is less than the lower threshold, a malfunction is detected. If an individual temperature problem is detected in all four channels, a malfunction is detected and a DTC is stored.