Opel Frontera UBS. Manual - part 129

4B1–6 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)

Transfer Position Switch

412RW040

Legend

(1) Ball

1. With ball being free.

A–B : There is continuity.

2. With ball forced into the switch.

A–B : No continuity.

3. If 1) and 2) fail, replace with a new switch.

4B1–7

DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)

Shift on the Fly System (Push Button Type)

Outline of Shift on the Fly System (Push Button Type)

The shift on the fly system switches between 2 wheel
drive (2WD) and 4 wheel drive (4WD)  electrically by
driver’s pressing the 4WD switch (push button type) on
instrument panel.
This system controls below operations. (Shifting between
“4H” and “4L” must be performed by transfer control lever
on the floor.)

1. Shifting the transfer front output gear (Connecting to,

and disconnecting from, front propeller shaft by motor
actuator).

2. Retrial of shifting the transfer front output gear.
3. Connecting front wheels to, and disconnecting them

from, the front axles by vacuum actuator.

4. Indicator on instrument panel.
5. 4WD out signal to other Electronic Hydraulic Control

Unit (If anti–lock brake system is equipped).

System Diagrams

412RW050

4B1–8 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)

Normal Operation

The motor actuator mounted on transfer rear case is
driven by signal from 4WD switch on instrument panel.
After complete the connecting transfer front output gear
to, or disconnecting it from, front propeller shaft, condition

of the transfer position switch changes.  The vacuum
solenoid valve (VSV) is driven by the signal from transfer
position switch and the vacuum actuator connects front
wheels to, or disconnect them from, front axles.

Time Chart of Shifting Under Normal Condition

F04RW002

4B1–9

DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)

Retrial

The motor actuator starts transfer gear shifting after
signal from 4WD switch on instrument panel has been
received.  But the shifting may be impossible in cold
weather or under high speed condition.  When 2 seconds
have passed since transfer gear shifting started and the
transfer position switch dose not turn on (the gear
engagement is not completed), the motor reverses its
rotation for 1.2 seconds and tries again to shift transfer

gear.  This procedure is repeated 3 times in maximum.
While this procedure, 4WD indicator lamp blinks by 2 Hz.
If the transfer position switch does not turn on after
aforementioned procedure has been repeated 3 times,
the gear shifting is stopped and 4WD indicator lamp’s
blinking changes from 2Hz to 4Hz to notify driver that the
gear shifting is stopped.  This blinking of indicator lamp
continues until 4WD switch is returned from 4WD to 2WD.

Time Chart of Shifting Under Severe Condition (re-
trial)

F04RW003