General Description

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. However, steep grades may cause variations in the selected speeds. The electronic cruise control system has the capability to CRUISE, COAST, RESUME SPEED, ACCELERATE, and TAP-UP or TAP-DOWN.

The main parts of the cruise control system are:
^ The Powertrain Control Module (PCM)
^ The function control switches
^ The stoplamp switch assembly
^ The Clutch Pedal Position sensor (CPP), if equipped

The cruise control system uses the PCM to maintain the desired vehicle cruise speed and operation and to vary the throttle opening in each different cruise control mode. The PCM also monitors vehicle speed and cruise control operation. The throttle actuator operates in response to the PCM, to maintain the desired cruise speed. The throttle actuator motor moves the throttle blade. The PCM assembly contains a low speed limit which will prevent system engagement below a minimum speed of 40 km/h (25 mph). The PCM assembly is not serviceable.

Cruise control operation is obtained through the function control switches located on the multifunction turn signal lever. The cruise control function control switches include the ON/OFF, SET/COAST, R/A (resume/accelerate). The switch assembly provides driver control of the cruise control system.

The multiple function stop lamp switch or CPP switch if equipped, is used to disengage the cruise control. A cruise control release switch circuit and a stoplamp switch circuit are used. The stop lamp and CPP switches are mounted to the brake pedal bracket. To disengage the system the driver presses the brake pedal or clutch pedal, if equipped. The speed of the vehicle at brake actuation will be stored in the memory of the TAC module.

With cruise control, the vehicle can maintain a speed of about 40 km/h (25 mph) or more without keeping your foot on the accelerator. When the driver turns off the cruise control ON/OFF switch or ignition switch, the cruise control turns off. The vehicle speed stored in the memory of the PCM will be lost.

Ignition positive voltage is supplied from the cruise fuse, to the cruise control switch. The PCM is grounded to G103. When the cruise control ON/OFF switch is on, ignition positive voltage is applied to the cruise on switch signal terminal of the PCM. If the driver has not pressed the brake pedal or clutch pedal if equipped, ignition positive voltage is supplied through the stop lamp switch, to the TCC/Brake pedal switch signal and clutch pedal position signal, if equipped, terminals of the PCM. Cruise control is canceled when the driver presses either the brake pedal or clutch pedal, if equipped. The stop lamp switch closes, applying battery positive voltage to the stop lamp signal circuit of the PCM. Voltage is also removed from the TCC/Brake pedal signal circuit and the clutch switch signal circuit, if equipped, at the PCM. When pressing the SET/COAST button on the multifunction turn signal lever, ignition positive voltage is applied to the set/coast switch signal terminal of the PCM. When pressing the R/A (resume/accelerate) on the control switch, ignition positive voltage is applied to the resume/accelerate switch signal terminal of the PCM.

When the cruise switch is in the ON position, and the driver presses the SET/COAST button, the switch signal notifies the PCM that the cruise control is requested. The PCM then checks to see that the cruise control enable criteria is met. If the cruise control criteria has been met the PCM engages cruise control and sends a class 2 message to the Instrument Panel Cluster (IPC) to illuminate the cruise light, if equipped

The PCM will inhibit cruise control:
^ Vehicle speed is less than 40 km/h (25 mph).
^ In PARK, REVERSE, NEUTRAL, or 1st gear
^ Low engine RPM
^ High engine RPM (fuel cut-off)
^ Vehicle speed is too high.
^ An over or under charged battery voltage condition exists.
^ Antilock brake system/traction control system is active for more than 2 seconds.

If the PCM determines that any of the cruise control inhibit conditions are present, the PCM will disengage the cruise control. If the PCM disables the cruise control for an inhibiting event it will record the reason for disengagement in the Disengage Definition data file.