Diagnostic Aids

Code P1568 may set if cruise control throttle cable binds or intermittently sticks. Code P1568 can also be set by manually compressing cruise servo to raise engine speed. Outside interference such as a CB antenna lead near PCM wiring harness may induce a false SPS signal and set Code P1568.

An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside insulation. Check for:

• Poor Connection Or Damaged Harness
  
  Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.

Fig 1: Code P1568A Schematic (3.8L) Cruise System Problem (SPS Indicated High)

Fig 2: Code P1568A Flow Chart (3.8L) Cruise System Problem (SPS Indicated High)