Cruise Control

NOTE: Depressing the OFF switch or turning off the ignition switch will erase the set speed stored in the PCM.

When the cruise control is selected by depressing the ON switch, the PCM allows a set speed to be stored in PCM RAM for cruise control. To store a set speed, depress the SET switch while the vehicle is moving at a speed between 35 and 85 MPH. In order for the cruise control to engage, the brakes cannot be applied, nor can the gear selector be indicating the transmission is in Park or Neutral.

The cruise control can be disengaged manually by:

Stepping on the brake pedal.
Depressing the OFF switch.
Depressing the CANCEL switch.
Depressing the clutch pedal (if equipped).

For added safety, the cruise control system is programmed to disengage for any of the following conditions:

An indication of Park or Neutral.
A rapid increase RPM (indicates that the clutch has been disengaged).
Excessive engine RPM (indicates that the transmission may be in low gear).
The speed signal increases at a rate of 10 MPH per second (indicates that the coefficient of friction between the road surface and tires is extremely low).
The speed signal decreases at a rate of 10 mph per second (indicates that the vehicle may have decelerated at an extremely high rate).

Once the cruise control has been disengaged, depressing the RES/ACCEL switch (when speed is greater than 30 mph) restores the vehicle to the target speed that was stored in the PCM. While the cruise control is engaged, the driver can increase the vehicle speed by depressing the RES/ACCEL switch. The new target speed is stored in the PCM when the RES/ACCEL is released. The PCM also has a "tap-up" feature in which the vehicle speed increases at a rate of approximately 2 mph for each momentary switch activation of the RES/ACCEL switch. A "tap-down" feature is used to decelerate without disengaging the cruise control system. To decelerate from an existing recorded target speed, momentarily depress the COAST switch. For each switch activation, speed will be lowered approximately one mph.

If the vehicle operator repeatedly presses and releases the SET button with their foot off of the accelerator (referred to as a "lift foot set"), the vehicle may accelerate and exceed the desired set speed by up to 5 MPH (8 KM/H). It may also decelerate to less than the desired set speed, before finally achieving the desired set speed. The cruise Control System has an adaptive strategy that compensates for vehicle-to-vehicle variations in speed control cable lengths. When the speed control is set with the vehicle operators foot off of the accelerator pedal, the cruise control thinks there is excessive cruise control cable slack and adapts accordingly. If the "lift foot sets" are continually used, a cruise control overshoot/undershoot condition will develop. To "unlearn" the overshoot/undershoot condition, the vehicle operator has to press and release the set button while maintaining the desired set speed using the accelerator pedal (not decelerating or accelerating), and then turning the cruise control switch to the OFF position (or press the CANCEL button if equipped) after waiting 10 seconds. This procedure must be performed approximately 10-15 times to completely unlearn the overshoot/undershoot condition.