DTC P0605: Internal Control Module Read Only Memory (ROM) Error: General Description

An PCM ROM malfunction is detected by using a checksum technique for verifying data. Digital data is composed of zeros and ones. A checksum is the total of all ones in a string of data. By comparing the checksum value with a stored value, a malfunction can be detected. An PCM RAM malfunction is detected by writing a known string of data and comparing it with a stored string of data.