freightliner Columbia - Rear Axles

heading "Engine Braking Systems" for additional
information.
Exhaust Brake Switch, Optional
The optional exhaust brake is controlled by a dash-
mounted paddle switch to help slow the vehicle when
the throttle is released.
Engine Fan Switch, Optional
The engine cooling fan can be turned on by the en-
gine fan (ENG FAN) switch. The fan will continue to
operate for a set amount of time and then turn off
unless the coolant temperature is high enough to
continue the fan operation.
Aftertreatment System (ATS)
Request/Inhibit Regen Switch
A parked regen of the ATS can be initiated with the
request/inhibit regen switch. It may also be used to
inhibit the vehicle from performing an automatic
regen. See Fig. 2.33.
The style and function of switch will vary with the en-
gine make and model. See the engine operation
manual for operation details.
Controlled Traction Differential Control
Valve Switch
A controlled traction differential feature is included or
available as an option on some rear axles. A control
valve switch engages and disengages the controlled
traction feature to cause the axle shafts to rotate to-
gether. See Fig. 2.34. The controlled traction, or dif-
ferential lock, should only be engaged when the ve-
hicle is moving slowly at low throttle to avoid causing
internal axle damage. The differential lock must only
be used for adverse road conditions. The use of the
lock increases the turning radius and affects the ve-
hicle handling. A guard is positioned around the
switch to minimize accidental activation. See Chap-
ter 9 for complete operating instructions.
06/03/99
f270065
R
N
D
1
2
3
4
5
6
7
1. Upshift (in manual mode, pull upward)
2. Steering Wheel
3. Reverse Position
4. Neutral Position
5. Drive Position
6. Downshift (in manual mode, push downward)
7. Steering Column
Fig. 2.32, SmartShift Control Operation (Eaton Fuller
AutoShift control, showing only R, N, D positions)
f610848
10/02/2006
Fig. 2.33, Request/Inhibit Regen Switch
09/26/95 f350142
Fig. 2.34, Controlled Traction Differential Switch
Instruments and Controls Identification
2.28