tow bar KIA CARNIVAL 2007 Workshop Manual

fluctuated even though turns on or off the input signal. The electrical ‘time constant’ is much more fast than one of
mechanical so the frequency of VFS is extremely higher than the conventional PWM type.
Characteristics of Bosch VFS:
Supply pressure : 700~1600kPa
Control pressure: typically 600~0 kPa
Current range: typically 0~1,000 mA
Dither frequency: Up to 600 Hz
Dimension: 32 mm protrusion reach 42 mm
The reducing pressure will be supplied to the ‘Supply’ port of the VFS valve on the above illustration to control the line
pressure.
Reducing pressure
Function
As same as one of Alpha or Beta automatic transaxle system, this reducing valve length can be adjusted by rotating
the screw on the picture. As you rotate the screw toward clockwise by 90°, the reducing pressure will increase about
1.0bar. However, the reducing pressure is used just as a ‘supply pressure’ for the solenoid valves (except
Low&Reverse, Reduction and Damper Clutch control solen), so this may not be handled to rotate in the field service
shop. VFS is operated based on the ‘supply pressure’ and it outputs the ‘control pressure’ to control the regulator
valve indirectly. While developing the VFS system, the line pressure was used as a ‘supply pressure’ for VFS and
other solenoid valves but it has been changed into additional ‘reducing pressure’ because the line pressure is variably
changed by VFS so the control pressure becomes unstable and some hydraulic pressure oscillation occurred. That is

(3)If a vehicle stays under extremely hot or cold environment, the detection range may be reduced. It will be
restored at the normal temperature.
(4) When heavy cargo is loaded in rear cargo area, it changes the vehicle balance, which reduces the detection
range.
(5) When other vehicle's horn, motor cycle engine noise, or other ultra - sonic wave sources are near.
(6) Under heavy rain.
(7) When reversing towards a vertical wall and the gap between the vehicle and the wall is 15cm. (Alarm may
sound despite the absence of a barrier)
(8) If radio antenna is installed at the rear.
(9) If the vehicle rear wiring is re- routed or electrical component is added at the rear part.
(10) Vehicle balance is changed due to the replacement of the rear spring.
(11) The unit will operate normally when the vehicle speed is 5km/h or less.
Above this speed, the unit may not operate normally
8. Check the rear bumper for installation condition and deformation. If installed improperly or the sensor orientation is
deviated, it may cause malfunction.
9. Be careful not to apply shock during sensor installation on the transmission or reception unit.
10. When adding electrical devices or modifying harness at the rear body of the vehicle, ensure not to change the
transmission and reception unit wiring.
Tagging the transmission side and reception side, it may cause malfunction.
11. High power radio transmitter (above 10W) may cause malfunction. Do not install it on the vehicle.
12. Be careful that excessive heat or sharp objects shall not touch ultrasonic sensor surface.
Do not cover the sensor opening or press the sensor.