P0AC8

DTC P0AC8

CIRCUIT DESCRIPTION
The following DTCs are for the battery temperature sensors located in the energy storage box (ESB) on each battery:
- P0A9E is for the hybrid battery 1 temperature sensor circuit high voltage.
- P0A9D is for the hybrid battery 1 temperature sensor circuit low voltage.
- P0AC8 is for the hybrid battery 2 temperature sensor circuit high voltage.
- P0AC7 is for the hybrid battery 2 temperature sensor circuit low voltage.
- P0ACD is for the hybrid battery 3 temperature sensor circuit high voltage.
- P0ACC is for the hybrid battery 3 temperature sensor circuit low voltage.

Battery temperature sensors allow the energy storage control module (ESCM) to monitor the temperature of the batteries in the energy storage box. The module applies 5 volts to internal input resistors that are connected to the signal circuits of the battery temperature sensors. The module provides ground to the battery temperature sensors through the low reference circuit. The ESCM monitors the voltage drops across the battery temperature sensors and uses the inputs for hybrid calculations. When the battery temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the battery temperatures are hot, the resistances of the sensors are low and the voltage signals are low.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- DTC P0A9D Hybrid Battery 1 Temperature Sensor Circuit Low Voltage
- DTC P0A9E Hybrid Battery 1 Temperature Sensor Circuit High Voltage
- DTC P0AC7 Hybrid Battery 2 Temperature Sensor Circuit Low Voltage
- DTC P0AC8 Hybrid Battery 2 Temperature Sensor Circuit High Voltage
- DTC P0ACC Hybrid Battery 3 Temperature Sensor Circuit Low Voltage
- DTC P0ACD Hybrid Battery 3 Temperature Sensor Circuit High Voltage

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- The engine has been running for 30 seconds.

CONDITIONS FOR SETTING THE DTC
The ESCM determines that the value of the Battery Temperature parameter is less than -40°C or greater than 85°C.
- P0A9E is set when the ESCM has determined that the battery 1 temperature sensor value is greater than 85°C.
- P0A9D is set when the ESCM has determined that the battery 1 temperature sensor value is less than -40°C.
- P0AC8 is set when the ESCM has determined that the battery 2 temperature sensor value is greater than 85°C.
- P0AC7 is set when the ESCM has determined that the battery 2 temperature sensor value is less than -40°C.
- P0ACD is set when the ESCM has determined that the battery 3 temperature sensor value is greater than 85°C.
- P0ACC is set when the ESCM has determined that the battery 3 temperature sensor value is less than -40°C.

CONDITIONS FOR CLEARING THE DTC
- The DTC will become history if the ESCM no longer detects a fault.
- The history DTC will clear after 40 fault-free ignition cycles.
- The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Step 1 - Step 10:

Step 11 - Step 14:

The numbers below refer to the step numbers on the diagnostic table.
4. This step verifies that the temperature displayed is not within the calibrated range.
5. This step tests for the proper operation of the circuit in the high voltage range.
6. This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.