Isuzu 1999 RODEO Workshop Manual page 272

Warning at "4L" position :In view of the shifting
mechanism of transfer, the gear shifting from 4WD to
2WD at "4L" condition is impossible. Therefore, the
transfer position switch can not be turned off by 4WD
Time Chart of Shifting from 4WD to 2WD at "4L" Condition
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)
120 ms
240 ms
switch when vehicle is in "4L" condition. In the case this
condition continues for 2 seconds, the shifting to 2WD is
stopped and the indicator lamp's blinking changes from
2Hz to 4Hz to notify driver of wrong operation.
Vehicle Condition
2WD
4WD
DRIVELINE CONTROL SYSTEM
Transfer position switch
2WD (Open)
4WD (Close)
4B–5
F04RX005
Front axle switch
2WD (Open)
4WD (Close)