6-20 CHASSIS ELECTRICAL
CRUISE CONTROL
I See Figure 50
The cruise control system on the Previa models is electronicallylkon-
trolled.
The cruise control system functions by various components suqj as:
- Cruise control ECU
- Cruise control switch
- Stop light switch
- Neutral safety switch
- Parking brake light switch
- Starter relay
- Vehicle speed sensor
- Actuator
- Throttle Position sensor
These components together allow the system to work properly. Ifany ot
these components fail, the system will not function correctly.
The cruise control system allows you to cruise the vehicle at albesired
speed over 25 mph (40 km) even when your foot is off the acceleiitor
pedal. The cruising speed is maintained up or down grades within the
limits of the engine performance, although a slight speed change may
occur when driving up or down the grades. On steeper hills, a gre| ter
speed change will occur so it is better to drive without the cruise
control.
CRUISE CON
Problem
Will not hold proper speedCruise intermittently cuts outVehicle surgesJ/B and R/B No.lCruise Control Main & Control SwitchStarter RelayFig. 50 View of the cruise control system componentsROL TROUBLESHOOTING
Possible CauseCruise control inoperativeNote Use this chart as a guide.Incorrect cable adjustment
Binding throttle linkage
Leaking vacuum servo diaphragm
Leaking vacuum tank
Faulty vacuum or vent valve
Faulty stepper motor
Faulty transducer
Faulty speed sensor
Faulty cruise control module
Clutch or brake switch adjustment too tight
Short or open in the cruise control circuit
Faulty transducer
Faulty cruise control module
Kinked speedometer cable or casing
Binding throttle linkage
Faulty speed sensor
Faulty cruise control module
Blown fuse
Short or open in the cruise control circuit
Faulty brake or clutch switch
Leaking vacuum circuit
Faulty cruise control switch
Faulty stepper motor
Faulty transducer
Faulty speed sensor
Faulty cruise control module
Not all systerns will use the components listed