Test F: DTC P0A27 - Hybrid Battery Power Off Circuit

PINPOINT TEST F: DTC P0A27 - HYBRID BATTERY POWER OFF CIRCUIT

Normal Operation

With the engine running, the battery power off (BPO) function may be triggered by the front and/or rear inertia fuel shut off (IFS) switches opening, a high-voltage interlock circuit opening or the electrical interlock (EL I) circuit opening (fuse protected by the battery junction box [BJB] fuse 26 [5A]). The IFS switch opens and causes the BPO mode to occur, no DTCs are set. Also, if the IFS switch is open, a power reset indicator in the instrument cluster illuminates. The PCM monitors the frequency signal that the battery control module (BCM) sends out on the BPO circuit CDC05 (GY/VT).
- DTC P0A27 Hybrid Battery Power Off Circuit - the BCM will set this DTC if any of the following conditions are met:
- TBCM detects a thermistor temperature greater than 57°C (134°F) for at least one second
- Contactor control is reported as closed while contactor status confirmed is reported as open for 10 seconds
- High-voltage traction battery (HVTB) is overheated.
- It is possible for the PCM to set DTC P0A28 (Hybrid Battery Power Off Circuit Low) as a continuous fault.

This pinpoint test is intended to diagnose the following:

- Fuse
- Circuitry (to the PCM)
- HVTB

F1:

F2:

F3 - F4:

F5 - F6: