P068

Diagnostic Trouble Code P068:

Cruise Control Circuit:

CIRCUIT DESCRIPTION
This diagnostic test checks for a cruise control servo feedback reading significantly higher or lower than the commanded value for a period of time. If such a condition occurs, Code P068 is set and cruise control is disabled.

TEST CONDITION
Cruise control engaged.

FAILURE CONDITIONS
Case 1
1. Throttle position 20 degrees or greater.
2. The servo position sensor indicating a stroke at least 7% greater than the commanded value for 2 seconds.
Case 2
1. Cruise control servo commanded to 46% or less of maximum stroke.
2. The servo position sensor indicating a stroke at least 19% less than the commanded value for 10 seconds.

ACTION TAKEN
Case 1
PCM disables cruise control for the entire ignition cycle.
Case 2
PCM disables cruise control while Code P068 is current.

NOTES ON FAULT TREE
1. Checking if PS07 is able to fully retract cruise control servo.
2. Checking if PS07 is able to fully relax cruise control servo.
3. Checking if binding or a short to voltage on CKT 403 is keeping the cruise control servo from fully relaxing.