Dodge 2009 Ram Diesel Owner's Manual Supplement page 65

Overdrive Operation
The Overdrive automatic transmission contains an elec-
tronically controlled 5th and 6th (if equipped) speed
(Overdrive). The transmission will automatically shift
from DRIVE to Overdrive if the following conditions are
present:
• the shift lever is in DRIVE;
• the engine coolant has reached normal operating tem-
perature;
• vehicle speed is above approximately 38 mph
(61 km/h) for 5th gear and 50 mph (80 km/h) for 6th
gear;
• the "TOW HAUL O/D OFF" switch has not been
activated;
• transmission
has reached
temperature.
NOTE: If the vehicle is started in extremely cold tem-
peratures, the transmission shift schedule initially re-
stricts transmission operation in forward gear ranges to
3rd gear until the transmission fluid temperature rises to
a suitable level. During this condition, the ability of the
vehicle to accelerate under heavily loaded conditions
may be reduced. Refer to the "Note" under "Torque
Converter Clutch" in this section.
If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough, the "Transmission
Temperature Warning Light" may illuminate and the
transmission may downshift out of Overdrive until the
transmission cools down. After cool down, the transmis-
sion will resume normal operation.
normal operating
The transmission will downshift from Overdrive to Drive
if the accelerator pedal is fully depressed at vehicle
STARTING AND OPERATING 63
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