Advanced Diagnostics

Advanced Diagnostics - DTC P0A7F (78): Battery Module Deterioration






General Description
The capacity of the battery module is defined by upper and lower limits of the battery module voltage. When the battery deteriorates, the limits of the battery capacity are narrowed. Under specific driving conditions, the motor control module (MCM) monitors the maximum and minimum voltage of the battery module. The MCM computes the battery module electrical current value during operation to calculate the battery module capacity. If the calculated value is under the specification, a malfunction is detected and a DTC is stored.

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






Enable Conditions






Malfunction Threshold
The battery module capacity is less than 20 %.

Driving Pattern
1. Start the engine.
2. Hold the engine speed to 3,500 - 4,000 rpm (in P or N) until the IMA battery level indicator shows a full charge.
3. Drive the vehicle with the accessories on (blower fan MAX, headlights ON, etc.). Without turning the ignition switch to LOCK (0), accelerate and decelerate repeatedly under the condition to use IMA assist until the IMA battery level indicator shows one segment.

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the MCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.