This page is designed to help you to quickly and cheaply fix your “bad” Chrysler, Dodge, or Plymouth four-speed automatic transmission for your front wheel drive car or minivan. Here are the most likely culprits, each of which can probably be fixed either by you or by a local mechanic for under $100:Incorrect transmission fluid (cost: $40-60) – most common problem! Solenoid pack (cost: about $60-$150 plus labor. May just be clogged.) Computer needs retraining (cost: time) Ground strap broken/missing – may be misdiagnosed as needing a new transmission and/or computer! (cost: $10) Bad input sensor (according to D. Philbrook, very common!) – “Can be seen on scan tool screen as input rpm –if it’s 0, replace the sensor.” Computer firmware needs upgrade (cost: Chrysler dealer should do this for free; may be up to $200) Incorrect filter used Loose electrical connection (cost: time) Leaking seals (cost: rebuilding) Torque converter problems – see the bump shift section Note: if you are having the “bump shift” see the bump shift section, below News source: ALLPAR As detailed in a 1995 technical service bulletin, 18-24-95, many issues (including the infamous “bump shift”) can be resolved by updating the computer’s flash ROM (where possible), and carefully going through a retraining process. Dealers can and should do this free of charge before any other work is undertaken (except of course for the transmission fluid change). (See below for the retraining process).Michael Richards wrote: The Transmission Control Module (TCM) is another item that deserves mention. I found a TSB indicating a flash upgrade (software?) was needed to eliminate hard/erratic shift problems after 2 dealers told me I needed a $1600 transmission rebuild. I insisted they perform the upgrade first. The TCM refused to accept the upgrade so I had them replace it (they did it under protest). Now my transmission works like new. It cost ‘just’ $200. Something to consider.[If the transmission fails after takeoff, check”> the electrical terminal that bolts into the computer housing that is mounted on the transmission. This is an electrical terminal and it bolts on to the computer box that is below the radiator fan and mounted on the transmission. Because of the poor design of this terminal it becomes a well and holds water. This happend to me on my 1992 3.3 Voyager. The transmission would not change gears without turning off the ignition to reset the computer. I used air to blow it out and the problem was solved. [I discovered it when replacing the sensors based on the advice on your site.”> Webmaster note: Chrysler integrated their engine and transmission computers later in the decade.