Advanced Diagnostics

Advanced Diagnostics - DTC P15A4 (81): A/C Compressor Driver Relay Stays Activated






General Description
The A/C compressor driver controls switching of the A/C compressor contactor and detects arcing. When the A/C compressor contactor arcs, it may stick on, and the A/C compressor driver sends the sticking information to the battery condition monitor (BCM) module by the IMA-CAN communication. When the BCM module receives the sticking information, a malfunction is detected and a DTC is stored.

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






Enable Conditions






Malfunction Threshold
The BCM module receives A/C contactor sticking information.

Driving Pattern
1. Start the engine.
2. Let the engine idle for at least 5 minutes at an outside air temperature of 41 °F (5 °C) or more. (If the outside air temperature is 77 °F (25 °C) or more, idling is not necessary.)
3. Turn the auto A/C switch ON.
4. Set the A/C temperature to 77 °F (25 °C).

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected, the IMA system indicator comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the BCM module memory.

Conditions for clearing the DTC
The IMA system indicator is cleared if the malfunction does not return in the next trip in which the diagnostic runs. The IMA system indicator, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.