Diagnostic Aids

An intermittently binding or sticking throttle cable cam cause a Code 68 to set. Code can also be set by manually compressing servo to increase engine RPM. Outside interference such as CB antenna lead near PCM wiring harness may cause false servo position sensor signal and set Code 68.

Fig 1: Code 68, Schematic, Cruise System Problem Using Tech 1 3.8L

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 68, Flow Chart, Cruise System Problem Using Tech 1 3.8L

Courtesy of GENERAL MOTORS CORP.