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 cruise control module assembly | 
 
|     •  | The function control switches | 
 
|     •  | The cruise control release switch | 
 
|     •  | The stoplamp switch assembly | 
 
|     •  | The vehicle speed sensor | 
 
The cruise control system uses the cruise control module assembly to
maintain the desired vehicle cruise speed and operation. The cruise control
 module assembly has a controller and an electric stepper motor to vary the
  throttle in each different cruise control mode. The  controller monitors
   vehicle speed and operates the  stepper motor. The stepper motor operates
 in response to the controller, to maintain the desired cruise speed. The
   electric stepper  motor moves a strap that is attached to the cruise control
 cable  which moves the throttle linkage. The cruise control module assembly
  contains a low speed  limit which will prevent  system engagement below
a  minimum speed  of 40 km/h (25 mph). The module assembly is not serviceable.
The operation of the controller is controlled by the function control
switches located on the steering wheel. The cruise control    functional control
  switches include the ON/OFF, SET/COAST, R/A (resume/accelerate).  The switches
 provide driver control of the cruise control  system.
The cruise control release switch, cancel switch and stoplamp switch
are used to disengage the cruise control. A release switch assembly and a
  stoplamp switch assembly  are mounted on the brake pedal bracket and the
 cruise control cancel switch is located on the steering wheel. To disengage
 the system the driver  presses the brake pedal or presses the cancel switch.
 The  speed of  the vehicle at brake actuation will  be stored in the memory
  of  the cruise module.
With cruise control, you 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 on/off switch or ignition switch, the cruise control turns  off.
  The vehicle speed stored in the memory of the cruise module will  be  lost.
Ignition 1 voltage is supplied from the cruise control
fuse, to the cruise control module. The cruise control module is grounded
  to the chassis. When the cruise control ON/OFF switch is on, ignition 1
voltage   is applied to the cruise control on switch signal circuit of the
cruise control   module.  If the driver has not pressed the brake pedalor
cancel switch, ignition  1 voltage  is supplied  through theTCC/Brake (cruise
release) and cruise control  cancel  switchs, to the cruise release  signal
circuit  of the  cruise control  module. When the driver presses the   brake
pedal, battery  positive  voltage  is supplied  from the stop lamp fuse, 
through the closed  stop lamp switch  to the stop lamp switch signal circuit
 of the cruise  control  module. When  the SET/COAST button is pressed , ignition
 positive voltage is applied to  the cruise control set/coast switch signal
  circuit of the cruise control  module. When pressing  the R/A  (resume/accelerate),
ignition positive voltage  is applied to the cruise control resume/ accelerate
  switch signal circuit  of the cruise control module.
The cruise control module receives a vehicle speed signal input from
the Powertrain Control Module (PCM). In operation, the voltage varies between
 0 V and 5 V.
 The cruise control module, cruise engaged circuit, sends a signal to
the PCM when cruise is engaged. The cruise control module, cruise inhibit
  signal circuit, is a circuit used by the PCM to disengage cruise control
 when conditions inconsistent with cruise operation are present.
After the cruise control engaged criteria has been met and the cruise
ON and Set/Coast have been commanded, the cruise control module sends a signal
  to the PCM that the cruise control is engaged.The PCM then sends a class
 2 message to the instrument panel cluster (IPC) to illuminate the cruise
light.
 The PCM will inhibit cruise control:
|     •  | When vehicle speed is less than 40 km/h (25 mph). | 
 
|     •  | When PARK, REVERSE, NEUTRAL, or 1st gear is indicated.  | 
 
|     •  | With high engine RPM (fuel cut-off) | 
 
|     •  | When vehicle speed is to high | 
 
|     •  | When an over or under charged battery voltage condition exists | 
 
|     •  | Antilock brake system/traction control system is active for more
than 2 seconds | 
 
|     •  | A 6 MPH or more decrease in non-drive wheel speed in 0.4 seconds
with out seeing the extended brake travel contacts of the TCC/Brake switch
transition. | 
 
If the PCM determines that any of the cruise control inhibit conditions
are present, the PCM will disengage the cruise control . The PCM accomplishes
 this by opening the cruise control  inhibit signal circuit.