Circuit Operation

Cruise Control Module

The cruise control module assembly mounts to the engine side of the cowl. The assembly has an electronic controller and an electric stepper motor to vary the throttle with each cruise control mode. The module assembly is not serviceable. It must be replaced.

Release Switches

When the brake or clutch pedal is depressed, the release switch interrupts the voltage supplied to the cruise control circuit in the ECM. The engagement switch must be energized to return the cruise control to operation.

Vehicle Speed Sensor

The vehicle speed sensor produces an AC signal. The frequency of this signal is proportional to transmission output shaft speed. On two wheel drive vehicles, the VSS mounts to the automatic/manual transmission assembly. On four wheel drive vehicles, the VSS mounts to the transfer case.

The AC signal produced by the VSS is amplified and converted to a digital signal by the VSS calibrator module assembly. The signal is supplied to the ECM, cruise control module, and speedometer by the VSS calibrator module. The VSS calibrator module produces the signal by opening and closing internal solid-state switches to ground.

The signal to the ECM, cruise control module, and speedometer assembly pulses at a rate of 4,000 times per mile. The ECM, cruise control module, and speedometer assembly internally convert the number of pulses per mile per second to determine vehicle speed.

Vehicle Speed Sensor Calibration Module

The vehicle speed sensor (VSS) calibrator module receives a signal from the VSS indicating the speed of the vehicle. This signal is processed by the module assembly and supplied to the ECM, cruise control module, and the speedometer assembly. It is located on the left side of the instrument panel, near the parking brake.

Multifunction Lever

On/Off

The "ON" and "OFF" position slide switch, located on the multifunction lever assembly, controls electrical power to the cruise control system. When the switch is OFF the system cannot be engaged. When the switch is ON the system may be engaged by either the SET or RESUME switch at any speed above approximately 40 km/h (25 mph).

Set/Coast Button Switch

The cruise control SET/COAST switch controls three functions:

The Set Function

When the SET/COAST switch is depressed and then released, with vehicle speed above the low speed limit point, and the ON/OFF switch ON, the cruise speed will be set at the particular speed the vehicle was at when the button was released. Cruise speed will be within ± 1.6 km/h (1 mph) of the actual speed when engaged. The system will cruise until either the ON/OFF switch is moved to OFF, the ignition switch is turned off, and/or the SET/COAST button is pushed in fully and held. Pushing the brake or clutch pedal disengages the system, but the set speed is maintained in memory allowing a RESUME at a later time.

The Coast (Trim) Function

When the SET/COAST button switch is fully depressed, the driver can raise or lower his control speed. To increase control speed, the driver would accelerate to a new speed, fully depress the switch, so the VCM releases previously set speed, and release the button. Upon releasing the button, a new speed is set. An increased control speed can also be more easily set by the RESUME/ACCEL switch as described later. To decrease cruise speed, the SET/COAST switch is held in the depressed position, disengaging the cruise system, allowing the throttle to return to the idle position. When the vehicle has slowed to the desired lower cruise speed, releasing the switch will cause the system to cruise at the new speed.

The "Tap Down" Function

For this function to operate, the cruise must be engaged and operating. "Tapping down" means quickly pressing the SET/COAST button to the depressed position and quickly releasing it, or "tapping" the button. Do not hold the button in the depressed position or the system will revert to the "coast" mode. "Tap down" is a function in which cruise speed can be decreased by 1.6 km/h (1 mph) increments (one tap = 1 mph decrease). The system can "tap down" to a limited speed of 40 km/h (25 mph). Below this speed, cruise control will not operate.

Important: The accelerator may be depressed at any time to override the cruise system. Release of the accelerator will return the vehicle to the previous set cruise speed.

Resume/Accel Switch

The RESUME/ACCEL (R/A) switch controls three functions:

The Resume Function

If the cruise system has been disengaged by depressing the brake or clutch pedal, it may be reactivated by momentarily holding the RESUME/ACCEL switch. This will cause the vehicle to accelerate to the previously set speed and cruise at that speed. The resume function will not work if the cruise ON/OFF switch or the ignition switch has been cycled since the last time cruise was active or the vehicle speed is below the low speed lockout 40 km/h (25 mph).

The Accelerate Function

By sliding the RESUME/ACCEL switch and holding it, the vehicle will accelerate until the switch is released. The ON/OFF switch must be on and the vehicle speed must be above the low speed lockout 40 km/h (25 mph) for this function to operate.

The "Tap Up" Function

For this function to operate, the cruise must be engaged and operating. "Tapping up" means quickly pressing the slide switch toward the R/A position and quickly releasing it, or "tapping" the lever. Do not hold the lever in the R/A position or the system will revert to the "Accel" mode. "Tap up" is a function in which cruise speed can be increased by 1.6 km/h (1 mph) increments (one tap=1 mph increase). The system cannot "tap up" beyond 210 km/h (125 mph).