Pcm Code P064 - Cruise Control Engaged/Acceleration Too High: Notes
WARNING: This page is about a different car, the 1993 Cadillac Seville and 1993 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
PCM Code P064 will set when vehicle speed is increasing at a rapid rate (wheel spin). This protective measure prevents wheel spin on icy roads when cruise control is in operation.
If PCM Code PO75 is also present, check for sources of Electromagnetic Interference (EMI), such as VSS wires run along side spark plug wires or high power transmitters (mobile radios) operating in vicinity.