OK I just got finished rebuilding my wife's 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.
the reason that 'the transmission computer is always replaced when a
transmission goes out' is:
pre-96 TCM's did not have the 'quick-learn' feature
re-using the old TCM, you are stuck with the CVI's that were in it when the
transmission failed (CVI's can be thought of as the controller adapting to
this causes a severe bind-up on the 2-3 shift for the first 10-12 shifts,
until the CVI's 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
I guess what you are saying is that the TCM (Transmission Computer
Module?) doesn't 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 won't 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 ?
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.
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