Opel Frontera UE. Manual - part 1310

4B1–2 DRIVELINE CONTROL SYSTEM

Shift On The Fly System

Outline of Shift on The Fly System

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 axle motor actuator.

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

Unit.

System Diagrams

412RY00005

SECTION

4B1–3

DRIVELINE CONTROL SYSTEM

Normal Operation

The motor actuator mounted on the transfer rear case is
driven by a signal from the 4WD switch (when activated)
mounted on the instrument panel. Then the transfer
position switch changes when the front output gear is
connected (or disconnected when the 4WD switch is

deactivated) to the front propeller shaft. The axle
disconnect controller is driven by the signal from the
transfer position switch and the axle motor actuator
connects (or disconnects when the 4WD switch is
deactivated) the front wheels to the front axles.

Time Chart of Shifting Under Normal Condition

F04R100004

SECTION

4B1–4 DRIVELINE CONTROL SYSTEM

Retrial

The transfer motor actuator starts the transfer gear
shifting after a signal from the 4WD switch mounted on
the instrument panel has been received. However,
shifting may not occur in severe cold weather or under
high speed conditions. When 2 seconds have passed
since the transfer gear shifting has commenced and the
transfer position switch does not activate (the gear
engagement is not completed), the motor reverses its

rotation for 1.2 seconds and automatically repeats the
operation again for a maximum of 3 times (with the 4WD
indicator lamp blinking–2Hz). If after 3 times the transfer
position switch does not come on, the gear shifting will
stop and the 4WD indicator lamp will blink faster (4Hz) to
alert the driver that the gear shifting has stopped. The
lamp will continue to blink until the driver deactivates the
4WD switch (to 2WD mode).

Time Chart of Shifting Under Severe Condition (retrial)

F04R100002

SECTION

4B1–5

DRIVELINE CONTROL SYSTEM

Warning at “4L” position : Shifting from 4WD to 2WD
while at “4L” operation is not possible. While at 4WD in the
“4L” operation, the transfer position switch cannot be
deactivated. If the 4WD switch was pressed to deactivate

the 4WD operation while in ”4L”, then the 4WD indicator
lamp will blink faster (from 2Hz to 4Hz) to alert the driver of
the wrong operation and the 4WD to 2WD mode will
cancel.

Time Chart of Shifting from 4WD to 2WD at “4L” Condition

F04R100003

4WD out signal to other Electronic Hydraulic Control
Unit : ECU of shift on the fly sends 4WD out signal to
other Electronic Hydraulic Control Unit as below.

4WD out signal

(Period)

Vehicle Condition

Transfer position switch

Front axle switch

120 ms

2WD

2WD (Open)

2WD (Open)

240 ms

4WD

4WD (Close)

4WD (Close)

SECTION