Circuit Operation

Cruise Control is a speed control system that maintains a desired vehicle speed under normal driving conditions. However, steep grades up or down may cause variations in the selected speed. The electronic cruise control system has the capability to cruise, coast, resume speed, accelerate, and tap-up and tap-down.

An Electronic Controller and Electric Motor are contained in the Cruise Control Module. The controller monitors vehicle speed and operates the electric motor. In response to the Controller, the motor moves a connecting strap that is attached to the Cruise Control Cable. The Cable moves the throttle linkage to vary throttle position in order to maintain the desired cruise speed. The Cruise Control Module contains a low speed limit which will prevent system engagement below a minimum speed of approximately 40 km/h (25 mph). The module is controlled by mode control switches located on the Steering Wheel. Cruise Control is in Standby Disabled mode until all conditions inconsistent with Cruise Control operation are cleared.

With the Ignition Switch in RUN, battery voltage is applied to terminal F of the Cruise Control Module. When the ON/OFF Switch is pressed ON, battery voltage is applied to terminal A of the Cruise Control Module. If the brake pedal is not depressed, battery voltage is present at module terminal D. If the brake pedal is depressed, battery voltage is present at module terminal G.

When the Resume/Accel Switch is moved to the R/A position, battery voltage is applied to terminal C of the module. With the Set Switch depressed, battery voltage is present at module terminal B. Cruise Control Module Connector terminal K is the speed signal terminal. In operation, voltage will oscillate between a high of battery voltage and a low of 0.5 volts. Ground is at Module terminal E. Terminal J is used to signal the Powertrain Control Module (PCM) when Cruise Control is engaged. The PCM will then determine the correct shift pattern for the transmission. Terminal H is used by the PCM to Inhibit Cruise Control when conditions not consistent with cruise operation are present.

The PCM will inhibit Cruise Control when:
^ The engine is OFF.
^ he Automatic Transaxle is in PARK or NEUTRAL.
^ There is high engine RPM (fuel cut-off).
^ There is high vehicle speed (fuel cut-off).
^ The PCM sets certain DTCs or other failure records.

Refer to Engine Controls Diagnostic System Check. Computers and Control Systems

When the PCM enables Cruise Control, it also commands the Body Function Controller (BFC) via the Class 2 Serial Data Line to turn the Instrument Cluster CRUISE Indicator on via the SPI Serial Data Line.