Description & Operation

WARNING: Vehicles are equipped with Supplemental Inflatable Restraint (SIR) system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.

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

Main components of cruise control system are:

Cruise Control Module (CCM).
Function control switches.
Cruise control release switch.
Brakelight switch assembly.
Vehicle speed sensor.

Cruise control system uses CCM to maintain desired vehicle cruise speed and operation. CCM has a controller and an electric stepper motor to vary throttle in each different cruise control mode. Two components in module assembly help to do this electronic controller and electric stepper motor. Controller monitors vehicle speed and operates stepper motor. Stepper motor operates in response to controller, maintaining desired cruise speed. Electric stepper motor moves a strap that is attached to cruise control cable which moves throttle linkage. CCM contains a low speed limit which will prevent system engagement below a minimum speed of 25 MPH. CCM is not serviceable.

Operation of controller is controlled by function control switches located on multifunction switch. Cruise control functional control switches include ON/OFF, SET/COAST, R/A. Multifunction switch assembly provides driver control of cruise control system.

Cruise control release switch and stop lamp switch are used to disengage cruise control. Release switch assembly and stop lamp switch assembly are mounted on brake pedal bracket. To disengage system driver presses brake pedal. Speed of vehicle at brake actuation will be stored in memory of CCM.

With cruise control on a speed of about 25 MPH or more may be maintained. When driver turns off cruise control ON/OFF switch or ignition switch cruise control turns off, and vehicle speed stored in memory of CCM will be lost.

Ignition 1 voltage is supplied from CRUISE fuse (10-amp), to CCM. CCM is grounded to chassis. When cruise control ON/OFF switch is on, ignition 1 voltage is applied to cruise on switch signal circuit of CCM. If driver has not pressed brake pedal, ignition 1 voltage is supplied through cruise control release switch, to cruise control release signal circuit of CCM. When driver presses brake pedal, battery voltage is supplied from STOP HAZARD fuse (15-amp), through closed brakelight switch to brakelight switch signal circuit of cruise control module. When SET/COAST button is pressed, ignition 1 voltage is applied to set/coast switch signal circuit of CCM. When pressing resume/accelerate button, ignition 1 voltage is applied to resume/accelerate switch signal circuit of CCM.

CCM receives a vehicle speed signal input from Powertrain Control Module (PCM). In operation, voltage varies between 0-5 volts.

CCM cruise engaged signal circuit, sends a signal to PCM when cruise is engaged. CCM cruise cancel signal circuit, is a circuit used by PCM to inhibit cruise control when conditions inconsistent with cruise operation are present.

PCM will inhibit cruise control when:

When vehicle speed is less than 25 MPH.
When PARK, REVERSE, NEUTRAL, or 1st gear is indicated.
With low engine RPM.
With high engine RPM e.g. fuel cut-off.
When vehicle speed is too high.
When an over or under charged battery voltage condition exists.
Anti-lock brake system/traction control system is active for more than 2 seconds.

If PCM determines that cruise control inhibit condition is present, PCM will disengage cruise control. PCM accomplishes this by opening cruise control inhibit signal circuit. If cruise engaged signal, sent by CCM to PCM, indicates that cruise control is still engaged after PCM has requested that cruise control disengage, PCM sets a DTC.