Description

DESCRIPTION
The cruise control system is used to control vehicle speed to a user selected value and an accuracy of 2 km/h (1 mph) on a flat level road (12% grade).

The system consists of a cruise control module; located in the passenger compartment on the driver's side above the accelerator pedal, control switches, cruise brake switch, PCM and software logic.

Unlike other cruise control systems, this system is completely electronic and does not require vacuum or a vacuum servo motor to control the movement of the throttle. To control throttle movement, a rod from the cruise control module pulls on the accelerator linkage at the accelerator pedal.

The cruise control system is integrated with the PCM. Cruise switch signals go directly to the PCM which uses engine control sensors to evaluate and command cruise movement and direction, enable/disable of the cruise module clutch.

The brake switch is an input to the cruise module as well as an input to the PCM. The switch is a normally open held closed switch which opens when the pedal is depressed. When the brakes are applied the clutch in the cruise module releases and the PCM interprets the signal as a request to disable the cruise module clutch.

There is no manual transmission clutch switch input to the cruise module nor the PCM. The PCM contains software which uses engine speed to calculate that the clutch pedal has been depressed. Engine rpm delta and variation of output speed versus engine speed from a known gear ratio will disengage the cruise module clutch. Some engine flare when depressing the clutch may be noticeable and should be considered normal.