DTC P0603: Engine Control Module (ECM) Internal Control Module Keep Alive Memory (KAM) Error: General Description

The engine control module (ECM) is equipped with a keep-alive memory. The data (control learn data etc) for powertrain control and information (Vehicle Identify Number (VIN) etc) related to the vehicle control is stored in the keep alive memory, so that it can be maintained even when power is not supplied to the ECM such as when the battery is disconnected. When power is restored to the ECM, the CPU retrieves the stored information from the keep-alive memory, but when the data retrieval process is not finished normally, a malfunction is detected and a DTC is stored.

The CPU writes data to the keep-alive memory from the CPU: Control related data is written when the ignition is turned on, and vehicle information when commanded from the HDS.

If the data writing process is not completed normally, a malfunction is detected and a DTC is stored.