Here is what I am getting on my daughter's 02 Stratus SE with the 2.4 and the auto 4 spd trans:

troubleshooting: P0841
definition: low/reverse (lr) pressure switch rationality fault
explanation: the tcm has detected a pressure switch open or closed at an incorrect time
probable cause:
1. open or short circuit condition
2. poor electrical condition
3. failed transmission solenoid/pressure switch assembly
4. faulty tcm/ecm

Does anyone know what any of that means? All of these items sound like things that can be fixed without an overhaul. Also, can the car be driven in this condition, or is it likely to go into limp mode at some inopportune time?

 

The TCM handles the function of the transmission. Likely it will need to be replaced. It's not an expensive part, and it's actually pretty easy to do too!

 

But how do I know whether the TCM is the problem, as opposed to the other items mentioned? Is there a test that I can do to determine what the real issue is, or will it have to go to a shop for that. Can the car be driven from Philly to Virginia without too much risk?

 

Everything described is IN the TCM. If the vehicle is still drivable, than the probability of the trans itself being broken is low. Of course, you can check for internal damage by taking the trans oil pan off and checking for metal fragments on the magnet (a fine powder like substance is OK, shards or chunks, not so much...) This could be a good time to change the fluid and filter too.

I just realized that you never actually described the SYMPTOMS of why you decided to check for codes. Were you not getting reverse, limp mode, or just the check engine light came on?

 

I haven't driven the car since Christmas time, so I am getting this from my daughter. She tells me that it is frequently jerky the first time you shift out of park to any other gear, and that it is acting "wierd". The check engine light is also on. She does not have any trouble getting around in it, but it is different enough that even a 21 year old girl with no interest in cars can tell the difference.