If all items are checked to be functioning correctly, then the PCM has to be substituted to test if that is the cause as it is part of the cruise control system. Any missing signal from the PCM would cause the cruise control to stop working.
One of the thing to test would be to get the freeze frame data to understand the situation when it occurs. That might show if any item malfunctioned without causing any trouble codes to be recorded when the cruise control failed.
Tuesday, September 22nd, 2009 AT 9:31 AM