Only runs in 1st and 2nd gear and reverse.
This is a fault mode in which the transmission either loses electrical
power or the PCM deactivates all of the electronics. The transmission
will default to max line pressure. The driver will have Reverse and
3rd, with manual 2nd available by putting the gearshift in 2 or 1
(doesn't matter). 1st, 4th, and TCC lockup will not be available. It
will not hurt the car to drive it like this for short periods, but use
manual 2nd to get the car moving, and be aware that the trans will
generate more heat than normal while operating in limp-home mode due to
increased torque converter slippage during 2nd gear starts and no
lockup in 3rd gear.
Trans shifts into gear harshly, car feels sluggish off the line,
No 1st, 4th or TCC lockup available, Manual 2nd, 3rd and Reverse are
only available gears, CEL is on: Transmission is either in limp-home
mode or has lost electrical power. If there are lots of error codes in
the PCM, check the under hood fuse that powers the transmission, and if
it pops again, look for a short in that circuit like an O2 sensor
harness touching exhaust. Otherwise, check PCM codes for a particular
fault in the transmission causing the PCM to put it in limp-home mode.
No 1st or 4th available; trans shifts 2nd to 3rd by itself in D or OD and locks the converter : ShiftA solenoid failed. Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.
Car goes into gear but feels very sluggish like the brakes are dragging,
but it will roll easily (starts out in 4th gear), you manually shift to
2 to get it moving, once it's moving you put it back in OD and the car
shifts 3rd to 4th on its own and locks the converter at the appropriate
time: ShiftB solenoid failed: Easy fix in the pan. Or a wiring problem
from PCM to trans.. or PCM.
Dec 14, 2009 |
2006 Hummer H3