What normally fails first on a modern day electronic transmission ?

From : transurgeon

Q: i guess what you are saying is that the tcm transmission computer module doesnt fail but that the internal mechanical parts fail just like in the older transmissions. it was interesting to read about how it works. so replacing a tcm before a failure wont stop a failure. does this mean that if i replaced the computer with a new one it will have the quick-learn feature in it or is a pre-96 transmission stuck with using a pre-96 tcm thanks ron transurgeon wrote the reason that the transmission computer is always replaced when a transmission goes out is pre-96 tcms did not have the quick-learn feature re-using the old tcm you are stuck with the cvis that were in it when the transmission failed cvis can be thought of as the controller adapting to clutch wear this causes a severe bind-up on the 2-3 shift for the first 10-12 shifts until the cvis adapt to the new unit; so severe in some cases that it almost throws you into the steering wheel it is possible to rapidly reset them by doing full-bore 3-1 down-shifts about 5-6 times followed by 5-6 of 4-2 full-bore down shifts but until it adapts you are scorching clutches on every shift with the quick learn you hook up a scan tool tell it to learn it instructs you to put the shifter in gears in a sequence the tcm learns that it has a new set of clutches in the pack and re-sets itself ok i just got finished rebuilding my wifes 1989 voyager or at least the engine and front-end. the transmission had been replaced a few years ago. now my question is does the electronics fail first then takes out the rest of the transmission because it is trying for reverse and forward at the same time or does the transmission just fail like most of mechanical transmission from heat i does seem that the transmission computer is always replaced when a transmission goes out. i am questioning if i should replace the computer now and maybe save a transmission bill 3 or 4 years down the road. i live in nr country that is no rust not no rednecks so the rest of the van is in very good shape or i would have never taken this project on. thanks ron .

Replies:

From : transurgeon

by the way martin my dodge custom van is a 1997 model with the 318 engine. it has been rather troublefree economical considering the nice power level and dependable. i was looking for a trailer hitch for this van and couldnt find any which was recommended or would fit with the factory step bumper. finally i saw a similar van with a trailer hitch and asked the nice lady if i could crawl up under and have a look...i got the hitch number ordered one online and installed it myself in about 15 minutes. the manufacturer says the hitch application is not recommended but i can tell you it works as it is and can be further strengthened with the addition of a couple of fabricated brackets. maybe you never want a hitch but if you do let me know and ill furnish the details. the responsibility for installing using and maintaining a hitch is yours. i take no responsibility for what anyone does in special applications of this sort. .

From : big al

big al wrote the reason that the transmission computer is always replaced when a transmission goes out is pre-96 tcms did not have the quick-learn feature re-using the old tcm you are stuck with the cvis that were in it when the transmission failed cvis can be thought of as the controller adapting to clutch wear this causes a severe bind-up on the 2-3 shift for the first 10-12 shifts until the cvis adapt to the new unit; so severe in some cases that it almost throws you into the steering wheel it is possible to rapidly reset them by doing full-bore 3-1 down-shifts about 5-6 times followed by 5-6 of 4-2 full-bore down shifts but until it adapts you are scorching clutches on every shift with the quick learn you hook up a scan tool tell it to learn it instructs you to put the shifter in gears in a sequence the tcm learns that it has a new set of clutches in the pack and re-sets itself seems to me they would have a way to reset the controller tcm to get it back to some safe generic settings. no wonder it costs so much to repair a car now. the scary part is what percentage of people working on this stuff actually know what they are doing everything is getting so frigging complicated. al yes it is and yes it isnt. i sure do prefer items like fuel injection and electronic spark control over the old mechanical ways but at this point i think i still prefer the older transmissions. .

From : transurgeon

is there anyway to look at the module and tell if it the ql version or not this transmission was replaced around 1998. it would be my luck that the tcm was old stock without the ql. thanks ron transurgeon wrote all of the replacements have the ql i guess what you are saying is that the tcm transmission computer module doesnt fail but that the internal mechanical parts fail just like in the older transmissions. it was interesting to read about how it works. so replacing a tcm before a failure wont stop a failure. does this mean that if i replaced the computer with a new one it will have the quick-learn feature in it or is a pre-96 transmission stuck with using a pre-96 tcm thanks ron transurgeon wrote the reason that the transmission computer is always replaced when a transmission goes out is pre-96 tcms did not have the quick-learn feature re-using the old tcm you are stuck with the cvis that were in it when the transmission failed cvis can be thought of as the controller adapting to clutch wear this causes a severe bind-up on the 2-3 shift for the first 10-12 shifts until the cvis adapt to the new unit; so severe in some cases that it almost throws you into the steering wheel it is possible to rapidly reset them by doing full-bore 3-1 down-shifts about 5-6 times followed by 5-6 of 4-2 full-bore down shifts but until it adapts you are scorching clutches on every shift with the quick learn you hook up a scan tool tell it to learn it instructs you to put the shifter in gears in a sequence the tcm learns that it has a new set of clutches in the pack and re-sets itself ok i just got finished rebuilding my wifes 1989 voyager or at least the engine and front-end. the transmission had been replaced a few years ago. now my question is does the electronics fail first then takes out the rest of the transmission because it is trying for reverse and forward at the same time or does the transmission just fail like most of mechanical transmission from heat i does seem that the transmission computer is always replaced when a transmission goes out. i am questioning if i should replace the computer now and maybe save a transmission bill 3 or 4 years down the road. i live in nr country that is no rust not no rednecks so the rest of the van is in very good shape or i would have never taken this project on. thanks ron .