[Bassasasin]

The Cruise computer is in the PCM. The PCM takes in the TPS, VSS signals and uses them. It seems the PCM notes too much acceleration/deceleration it won't set/engage. It makes sense if the VSS is erratic enough to fool the PCM but not the speedometer. Moreover from personal experience, the Multi-Function modules at the base of the turn signal lever fail by wrongfully engaging the accelerate/resume switch.