AUTOMATIC TRANSMISSION SERVICE GROUP
Technical Service Information
Copyright © 2001 ATSG
SELECT SHIFT TRANSMISSION (SST) SWITCHES(+and-)
SELECT SHIFT OPERATION (SST) SWITCHES(+and-)
BASIC RANGE SHIFTER
OPTIONAL RANGE SHIFTER
MANUAL SELECTOR LEVER OPTIONS
When in the Park position, there is no power flow
through the transmission and the parking pawl locks
the output shaft to the case. The engine may be started
and the key may be removed.
When in the Neutral position, there is no power flow
through the transmission, the output shaft is not held
and is free to turn. The engine may be started and the
key can not be removed.
When in these positions, gear ranges 1st through 5th
gears provide exactly the same function and ratios as
found in the "D5' or "D4" automatic mode positions.
When in the Reverse position, the vehicle may be
operated in a rearward direction at a reduced gear
ratio, and the back-up lamps are illuminated.
OPTIONAL MANUAL SHIFT SELECTOR
"P" = Park
"N" = Neutral
"D5" And "D4"
"R" = Reverse
The positions indicated by a (+) or a (-) allow the
driver to manually select the appropriate upshift (+) or
downshift (-). The PCM uses the input signals from
the SST+ and the SST- switches, along with other
vehicle inputs to determine which gear should be
Can only be entered from the "D5" position.
Transmission will not upshift or downshift unless
the selector lever is "Tapped" forward or
rearward. One tap forward (+) will allow trans to
upshift one gear range, and one tap rearward (-)
will allow trans to downshift one gear range.
A 2nd gear start is normal. A 3rd gear start up will
be allowed only if selected. A shift to first gear
with the vehicle at rest is never allowed. Upshifts
are allowed at any vehicle speed.
When downshifting at normal road speeds, the
transmission will only allow a downshift into the
next lower gear.
If the driver starts in 2nd gear and does not pass
60% throttle, the transmission will remain in 2nd
gear. No automatic upshift will occur.
If the driver passes 60% throttle, then a 2-1
automatic kickdown will occur, scheduled by the
PCM as used in "D5". Once this has occured, 1st
gear will hold until 2nd gear is selected by the
driver tapping the shift lever. No automatic
upshift is possible under these conditions. Once a
kickdown has occured, manual shifting in and out
of 1st gear is allowed until the next time the