Code P063, Vehicle Speed & Set Speed Difference Too High: Action

PCM disengages cruise control.

NOTE: Test numbers refer to numbers on diagnostic chart.

If Code P075 is set, diagnose code first because it can cause other speed related problems.
Checks if cruise control feedback is a value is zero to 6 or greater.
Checks if PCM and related circuit to cruise control servo is okay (4.6-5.1 volts).
Checks if circuit No. 398 for a short to voltage.
Checks if cruise control servo is able to respond correctly to signal from PCM.