Toyota 2009 Tundra Owner's Manual page 251

If the 4LO indicator light blinks
n
If the 4LO indicator continues to blink when shifting between 4H and 4L,
l
stop the vehicle completely, move the shift lever to N and operate the
switch again.
If the shift lever is moved before the 4LO indicator turns on/off, the trans-
l
fer mode may not be shifted completely. The transfer mode disengages
both the front and rear driveshafts from the powertrain and allows the
vehicle to move regardless of the shift position. (At this time, the indicator
blinks and the buzzer sounds.)
Therefore, the vehicle is free to roll even if the automatic transmission is in
P. You or someone else could be seriously injured. You must complete the
shifting of the transfer mode.
To complete the shifting, stop the vehicle completely, return the shift lever
to N, and confirm that the shift was completed (The indicator turns on/off).
If the engine coolant temperature is too low, the transfer mode may not
l
be able to be shifted. When the engine is warmer, operate the switch
again.
If the 4LO indicator light continues to blink even after attempting the above,
there may be a malfunction in the engine, the brake system or the four-
wheel drive system. In this case, you may not be able to shift between 4H
and 4L. Have the vehicle inspected by your Toyota dealer immediately.
Shifting to 4L
n
VSC is automatically turned off.
n Four-wheel drive usage frequency
You should drive in four-wheel drive for at least 10 miles (16 km) each
month.
This will assure that the front drive components are lubricated.
2-4. Using other driving systems
2
225