P1CF4

P1CF4-BATTERY TEMPERATURE SENSOR OUT OF RANGE HIGH

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Intelligent Battery Sensor (IBS) is mounted in-line with the negative Battery Cable. The IBS monitors the Battery state of charge and current draw. The IBS also has a built in thermistor that calculates the Battery temperature. This information is reported through a LIN BUS circuit to the Body Control Module (BCM). The BCM broadcasts the information to the Powertrain Control Module (PCM) over the CAN BUS.

- When Monitored:
The Powertrain Control Module use feedback from the IBS to monitor the Battery temperature under two different conditions. The first condition is at ignition on after a cold soak. The second condition checks for an implausible change in temperature.

- Set Conditions:
Condition one: The battery temperature is compared to the Engine Coolant Temperature (ECT) Sensor signal at key on after a cold soak. If the battery temperature is above the ECT temperature by a calibrated threshold, then the battery temperature is compared to the Ambient Air Temperature (AAT) Sensor in the same manner. If this comparison also fails, a fault is set. Condition two: If the change in temperature change is larger than a calibrated threshold within a calibrated period of time, then an IBS battery temperature failure shall be determined.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test
ACTIVE DTC

NOTE:
Diagnose and repair any ECT or AAT Sensor DTCs that may be present before continuing with this test procedure.

NOTE:
Diagnose and repair any BCM LIN BUS communication or IBS DTCs that may be present in the before continuing with this test procedure.

1. With the scan tool, view DTCs.

Is the DTC active?

Yes

- Replace the Intelligent Battery Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.