The other day I stopped at a stop sign and heard a loud clunk and my avenger stalled. I started it and accelerated. When I looked down the speedometer wasn't working, then when I got up to speed, my car wouldn't shift into 2nd(automatic). I drove home- about 5 miles- in 1st gear. no prior probs w/ tranny. A friend told me it could be the transmisson control module. Can anyone help?

 

It could be the TCM, clutch (relay) pack (makes the ratcheting/ticking noise you hear when you put it into gear), something seriously BAD (loud clunking noises are never good!). Have you had a look at it? Idle it, rev it, try to duplicate the problem? How long has it been since you changed your tranny fluid, what color is it, is there enough in the tranny?

BTW, this is tranny problem season (it seems)...you're not the only one, lol.

 

I haven't driven it since 3/21 for fear of the worst, but i had 2 other stops on the way home after that stop sign,nothing happened, except that it wouldn't shift out of 1st when i accelerated. It will idle fine, I do have park, rev,neu,d1,d2. I planned on getting the fluid changed at inspection next month(it has 97,000-had it since 51,000). the level is good, kind of dark.

 

I would have the fluid purged, the filter changed, and have them check for metal shavings. The A604 is picky though, it's a huge, heavy transmission that creates a lot of heat so make sure to use MOPAR tranny fluid ATF+3. The other ATF+3 stuff breaks down quick in our trannies. If you can afford it (please forgive me), go to the dealership and have them do it. Another thing you can do is buy the MOPAR ATF+3 from the dealership and have an independent garage put it in...what them though. Make sure that they use the stuff you bought and not theirs....paranoia, lol.
That clunk you heard may have been the tranny going into the lowest gear and came down with such force that it's stuck :dunno:...that's just a guess though. No one likes to hear "clunks" from their cars, it's usually a bad sign, lol.

 

Good news! that clunk was the speed output sensor going bad. I took it to the dealership. It's a $20 part and I got my car back within an hour. All that trouble for a stupid sensor. Still getting the fluid & filter changed, though(atf+3- already have it). It was $100 total after diagnostic,part,and labor.

 

Good news indead. Curious though, what part of the sensor made the clunk? Did something on it break off?

 

They told me that when the sensor quit, the tranny quit and my car stalled because of the sensor/ computer malfunction. The clunk was probably the tranny quitting while I was stopping at the stop sign, and it was in drive.

 

It probaly clunked when the sensor went out because the tcm didn't know what speed the tranny was at because it lost that data and it probaly tried to go into limp mode ie the not shifting past second. Having limp mode is probaly what saved your tranny.