Limp home mode...96 T&C

I recently had my trans rebuilt but even MORE recently, my "check engine"
light is always on and the trans goes in to "limp home" mode. For
example, if I'm going 60 and the system is working properly, the tach is
about 1800-1900. When I accelerate slowly, so the clutch doesn't release,
the tach goes up slowly. When there is a problem, and I accelerate slowly,
the clutch releases and the tach goes up quickly. When I slow down, it
goes into that "limp" mode and speeds up the engine, like it's locked in 2
gear. But sometimes, I can drive for a hundred miles and it does not do
any of the above, except for the "check engine" light being on. I know I
should take it to a shop but if anyone has any ideas of a way to massage
it--I'm 1000 miles from home.

TIA
John

 

By the way, it's the LXi with the 3.8 engine.

John

 

The longer you drive it like this the more chance of permanent (and very
costly) damage. Take it to a place that is very familiar with Chrysler
transmissions and have the trans computer scanned since it will record the
failure code whenever it goes into limp mode. If you are lucky it will be a
cheap and easily replaced sensor. Also, when posting for help, provide more
info like the engine and mileage.

Bob

 

I hope the rebuilder didn't put the wrong transmission fluid in your
T&C. It's got to be ATF+3 or ATF+4 and nothing else. Much has been said
about this, especially here: http://www.allpar.com/fix/trans.html

Ken

 

There are many component failures that could put it in limp home mode. I'm
going to ignore that and focus on things you can control. There are two
operating conditions that make the computer mad. These are:
1. The transmissions is slipping. In this case, the transmission is not
able to handle all the power the engine gives it. Because it senses input
and output speeds, it knows immediately when it is slipping. This might be
the case you are dealing with. I would suggest using 3rd gear instead of
overdrive and see if that helps at all. You want to be very easy with the
acceleration. If it's reliable in 3rd gear, that's good enough to get home.
2. The transmission delays too long without getting in a gear. If shifts
take too long, or if the transmission doesn't go into gear quickly when
commanded, the computer will decide to go to limp mode. The way you can
control this is to let off the gas so it can shift quickly. Don't do any
sudden braking, as this sometimes causes the pump to lose its prime. Also,
whenever it gets into limp mode due to bad shifting, simply shut the engine
off and start it back up and try again. If you can only get up to speed
once in every 3 or 4 tries, that's still good enough to get home.

 

I took the van to a trans shop. Fortunately, the warrantee was honored
there. They found that the speed sensor was bad. Evidently, the other
place had not replaced it. Now it shifts smoothly and on time and does
not slip at all in any gear or clutch. Thanx to all the guys on the NG
for the help.

John