Cruise Control System Operation

For diesel engine applications, the powertrain control module (PCM) takes the place of the cruise control module.

The PCM operates in the following manner:
1. Turn the CRUISE ON/OFF switch to the ON position.
2. When the SET button is activated, the PCM stores the last vehicle speed input from the Vehicle Speed Sensor (VSS) into a memory location. The PCM controls the electronic fuel injection pump in order to maintain the vehicle speed stored in memory.
3. The PCM increases and decreases fuel injection position depending on the load (going up or down a hill) to maintain vehicle speed.
4. If the CRUISE ON/OFF switch is in the OFF position or the brake is applied, the PCM will turn the cruise control system oft.