Ram Trucks 2012 Chassis Cab - Diesel Supplement - Manual (Page 72)

gear (when climbing a grade), or shifting to NEUTRAL
(when stopped in heavy traffic) can help to reduce this
excess heat generation.
During cold temperatures, transmission operation may
be modified depending on engine and transmission
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmission fluid
is warm (refer to the “Note” under “Torque Converter
Clutch” in this section). On cold starts below 41°F (5°C),
fifth and sixth gears may be inhibited briefly. During very
cold temperatures (-4°F [-20°C] or below), operation may
briefly be limited to third gear only. During this condi-
tion, the ability of the vehicle to accelerate under heavily
loaded conditions may be reduced. Normal operation
will resume once the transmission temperature has risen
to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in third gear regardless of which forward gear is selected.
If the vehicle enters Limp Home Mode at highway
speeds, it will initially engage fifth gear, until the vehicle
slows to a speed where third gear can be engaged. PARK,
REVERSE, and NEUTRAL will continue to operate. Limp
Home Mode allows the vehicle to be driven to an
authorized dealer for service without damaging the
transmission.
In the event of a momentary problem, the transmission
can be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
70 STARTING AND OPERATING