CRUISE CONTROL MODULE
Cruise Control Module (CCM) constantly monitors and compares set speed with actual vehicle speed from input sensors. When vehicle speed is greater than set speed, CCM activates actuator motor to close engine throttle valve, reducing vehicle speed. When vehicle speed falls to less than set speed, CCM activates actuator motor to open engine throttle valve, increasing vehicle speed.
CCM includes a self-diagnostic function. If cruise control system is canceled by any condition other than driver operation, CCM assumes a malfunction has occurred and may set a corresponding Diagnostic Trouble Code (DTC).
CRUISE ON-OFF Switch
CRUISE ON-OFF switch is the power switch for cruise control system. When ignition is turned off, CRUISE ON-OFF switch is also turned off. The switch remains off even when ignition is turned on again.
SET/COAST Position
When cruise lever is moved down to SET/COAST position while in cruise control mode (CRUISE indicator light on) and vehicle speed greater than 25 MPH, CCM stores vehicle speed and maintains that speed.
When cruise lever is moved down to SET/COAST position while in cruise control mode, actuator motor is energized to close engine throttle valve. Vehicle decelerates until switch is released. From then on, CCM stores new vehicle speed and maintains that speed.
RES/ACC Position
If cruise control system is canceled, vehicle set speed can be resumed and controlled at the previously set speed by moving cruise lever to RES/ACC (resume/accelerate) position. Set speed, however cannot be resumed and CCM speed memory will be cleared if vehicle speed drops to less than 25 MPH, ignition switch is turned off or CRUISE ON-OFF switch is pressed in OFF position.
When cruise lever is moved to RES/ACC position while in cruise control mode, actuator motor is energized to open engine throttle valve. Vehicle accelerates until switch is released. From then on, CCM stores new vehicle speed and maintains that speed.
CANCEL Position
When cruise lever is pulled toward you (CANCEL position), a cancellation signal is sent from CRUISE ON-OFF switch to CCM.
SERVO
Servo consists of an actuator motor, safety magnetic clutch, control arm and a position sensor. When servo receives a signal from Cruise Control Module (CCM), it engages safety magnetic clutch and activates motor. Motor causes control arm to move, which will open or close engine throttle valve.
When motor rotates forward, control arm also rotates (via safety magnetic clutch, gears and drive shaft). Control arm pulls a cable connected to engine throttle valve and opens valve accordingly. When motor rotates in a reverse direction, control arm also rotates in a reverse direction and engine throttle valve closes.
VEHICLE SPEED SENSOR
A Vehicle Speed Sensor (VSS) is located on extension housing of Electronic Automatic Transaxle (EATX). VSS rotor shaft is driven by a gear on EATX output shaft. For each shaft rotation, VSS sends a 4-pulse signal to instrument cluster. This signal is sent from instrument cluster to Cruise Control Module (CCM). CCM calculates vehicle speed from this pulse frequency.
SYSTEM TESTS
Note. Before performing any system test, perform system check. See TEST 1: SYSTEM CHECK . System tests should only be performed if system does not operate properly and no Diagnostic Trouble Codes (DTCs) are present.
| Symptom | Perform Test |
|---|---|
| System Check | 1 |
| Cruise Control Inoperative, Speedometer Operative | 2 |
| Cruise Control Does Not Resume Or Cancel | 3 |
| Cruise Control Warning Always On | 4 |
DIAGNOSTIC TROUBLE CODE (DTC) INDEX
CRUISE CONTROL SWITCH
For removal and installation of cruise control mode switch and combination switch, see STEERING COLUMN SWITCHES - Prizm article.