My TCM is finned (not sure if original, bought van used) and, based on posts, can be programmed. The van's transmission has been flawless over the last 20,000 miles I have owned it. Now has 90,000 miles. Can someone convince me to go ahead and take it in to get the upgrade if it doesn't have it already? I have serious reservations about letting anyone touch it, but a good argument might persuade....
Based on 18-24-95, a 1990 AS GV would require TCM part no. 4796122 w/ pin 49 disconnected. It is the one with 4 heat sinks (there is another later one with 7 apparently). It also says "Quick Learn Procedure" is not applicable to pre-1992. I would want to know if I buy a new TCM would it have the sofware and only require a swap w/o going to the dealer? If it did need a flash, the TSB says a CH5500 Flash Program Kit and Scant Tool DRBIII CH6000 would be needed.
First, I agree with mic_canic about "if it's not broke, don't fix it." If you take a vehicle that old into a dealer, you are just inviting them to suggest a lot of other "urgently needed repairs" that might end up costing more than the value of the vehicle.
Second, I have formed the general opinion that the TCM's (and the SMEC's) were not able to be "flashed" (reprogrammed) until about 1995. A recent purchase seems to back up that opinion.
I was recently able to purchase at a very reasonable price, a remanufactured TCM. (It never hurts to have a spare.) According to the ATSG handbook for the Chrysler A-604, the latest TCM part number for 1989 to 1991 transmissions with the 3.0L engine is 4761846. My TCM bears this part number and was rebuilt in 5/19/2000.
This TCM also contains a second, "authorized software update" sticker that has the part number 04796121. Taking the cover off, I can see through the clear potting compound, a large DIP chip that has been marked in large numbers by hand "121" which corresponds to the last three digits of the part number.
What I read into this is that the DIP chip is first programmed, then installed into the circuit board, which is then installed into the TCM housing.
Concerning TCM part numbers per the ATSG handbook. Good for 1989 to 1991 model year.
5234623 - Early 1989
5234649 - Early 1989
5234678 - Early 1989
4557120 - During 1989
4557585 - During 1990
4672104 - For 1991
4572002 - During 1991
4672105 - During 1991
4728600 - For 3.0L
4728598 - For 3.3L
4761846 - Latest for 3.0L
4761847 - Latest for 3.3L
Also, the only mention in the ATSG handbook about programming is for the 1993 TCM. All 1993 and later TCM's will have to have a pinion factor programmed in order for the speedometer and transaxle to function properly.
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