Diesel Data: Automotive Repair

Cruise Control Inoperative/Malfunctioning

CRUISE CONTROL INOPERATIVE/MALFUNCTIONING

DIAGNOSTIC AIDS
Perform the following in order to avoid a misdiagnosis:
- Inspect for proper operation of the brake lamps.
- EM on the vehicle speed sensor signal circuit may cause erratic cruise control operation.

CONDITIONS FOR ENABLING CRUISE CONTROL
- The vehicle speed is greater than 40 km/h (25 mph).
- The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
- The system voltage is within 9 volts and 16 volts.

TEST DESCRIPTION

Steps 1-8:




Steps 9-19:




Steps 20-28:




The numbers below refer to the step numbers on the diagnostic table.
8. This step tests the cruise control set(coast switch signal circuit for an open or for a high resistance.
9. This step tests the cruise control resume/accel switch signal circuit for an open or for a high resistance.
10. This step tests the ignition 3 voltage circuit for an open, for a short to ground, or for a high resistance.
28. DTCs will set in the PCM when you perform this table.