The engine will not rev up.

After battery disconnection and reassembly, the vehicle had no throttle response. Initial fault code P2100 indicated a throttle actuator control motor circuit issue. After replacing the throttle body and ECU, a new code P2176 appeared immediately upon key on, indicating that the throttle actuator idle position was not learned. Despite programming the new ECU and performing calibrations, there was still no throttle actuation or idle learn function available.