Action Taken:

Disengage cruise control.

Code EO63 will set and disengage cruise control if vehicle speed is 20 MPH more than cruise set speed. Code EO63 is designed to detect a cruise control problem that results in cruise overspeed or cannot hold speed.

NOTE: Test numbers refer to test numbers on diagnostic chart.

PCM data value ED70 displays servo position. Range is approximately 4-94 percent. If servo will not go to full stroke, the vacuum supply, servo, or vacuum brake release circuit are leaking.
Code EO63 will not be caused by vacuum leaks or vacuum supply problems. If can only be set by the vehicle exceeding set speed by 20 MPH.
Jumper cruise control servo terminal.

Fig 1: PCM Code EO63, Schematic, Vehicle Speed/Set Speed Difference Too High

Fig 2: Flow Chart, PCM Code EO63, Vehicle Speed/Set Speed Difference Too High