Advanced Diagnostics

DTC P0A27 (46): High Voltage Contactor/Bypass Contactor Stays Activated




General Description
When the ignition switch is turned off while the integrated motor assist (IMA) system is in an idle stop condition, the high voltage contactor opens and the stored charge in the PDU capacitor of the motor power inverter (MPI) module is consumed by the DC-DC converter, lowering the MPI module voltage. But if there is a high voltage contactor turn-on failure, the discharge mentioned above is impossible. Therefore, when the difference between the MPI module voltage value before the high voltage contactor opening process and the MPI module voltage value after the high voltage contactor opening process does not change after a specified time has passed, a high voltage contactor turn-on failure is detected and a DTC is stored.




Monitor Execution, Sequence, Duration, DTC Type, OBD Status




Enable Conditions

Malfunction Threshold
The difference of the MPI module voltage before the high voltage contactor opening process and the MPI module voltage after the high voltage contactor opening process is 3 V or less after at least 10 seconds have passed.

Driving Pattern
1. Turn the ignition switch ON.
2. Turn the ignition switch OFF, and wait for at least 15 seconds.
3. Turn the ignition switch ON.

Diagnosis Details

Conditions for illuminating the IMA system indicator
When a malfunction is detected, the I MA system indicator comes on and the DTC and the freeze frame data are stored in the BCM memory.

Conditions for clearing the IMA system indicator
The IMA system indicator will be cleared if the malfunction does not recur during the next trip in which the diagnostic runs. The IMA system indicator, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.