97 2500 4.10 auto transmission

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Nor my '03... there is for the [5]45RFE, though. Still - why would it be mentioned in the TSB?
What I want to know is... HOW exactly is it supposed to engage? What can be done electronically to prevent the application of 1st or 2nd gear?
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1st: lock the shift lever in reverse and neutral only? 2nd: Same thing, as it needs the rear clutch (1st) to function.
They could place a solenoid the VB and exhaust the feed to the rear clutch. Not too hard, but also knocks out all forward gears. Sorta kills the idea of limping home in 2nd and 3rd.
The only solenoids in the RE transmissions were for OD, TCC and governor pressure. There are only four pressure curves, one for cold, one for hot, one for WOT, and one for low range. So, where's "limp home"? They don't mention it in my FSM.
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So you are saying, in effect, that they did away with "limp home" mode?
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I dunno, I can only quote the TSB.
If you think about it for a minute you'll realize that the whole idea behind TSB's is to disseminate info not contained in the service manual. If the limp mode/limp-in mode were addressed in the FSM, there would be no need to rehash it in a TSB.
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If you think for a moment after reading the FSM and the complete description of operation, you might also come to the conclusion that there is no limp home mode. This is because it specifically details what the PCM is capable of doing.
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Perhaps because they choose not to name this condition in the FSM or maybe it is an unexpected condition that happens enough to be given a name. IF these things didn't happen, then there would be no need for any TSB's.
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The FSM is specific as to the operation of the trans and its solenoids. No "limp home" mode is described. If it is an "unexpected condition", then its not an operating mode of the PCM, but an unexpected condition.
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Isn't that the point of a TSB, Max, to talk about, explain, and define an unexpected condition? Perhaps this feature or behavior was not intended during the design of the system but that doesn't mean that it will not or cannot happen or that it will not later get a name if this unintended behavior is then shown to be consistent for a given set of conditions.
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If the condition is not expected, then it is not a "mode of operation", but an unexpected condition. Generally, technicians call "unexpected conditions" what they are, failures. In the specific case mentioned, the failure of the govenor pressure sensor, "limp home" is a nifty name for "the computer is confused and does not know what the governor pressure is". This is not a mode operation, but a lack of information.
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plus, the OP stated that it would not go into '1' even if the manual lever was put in '1'
this is one of those 'weird' failure modes, because the ML should over-ride gov pressure, unless the VSS was ALSO giving a squirrely reading, like telling the ECM that the vehicle was above 45 or so, at which point the GS would be wide-open and preventing the 1-2 shift valve from returning to the at-rest position
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Exactly how many TSB's concerning the automatic transmission have been predicted in the FSM and given names? If the material was covered in the FSM there would be no need for a TSB to rehash it.
I doubt if you'll find the term "broken camshaft" anywhere in a FSM, and nowhere will there be described a "mode of operation" that predictably leads to broken camshafts, but if there were a rash of such failures there would most likely be a TSB addressing it and the commonly used term "broken camshaft" would be used to describe the failure.
.
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While true, if it were actually a mode of operation, the FSM would cover it.

Problem is, you are referring to the PROBLEM as a mode of operation, not the mode of operation leading to the problem. Thus the reason why there are quotes around "limp in" in the TSB.
Again, if it was not part of the design, its a failure, not a mode of operation.
Is a flat tire a mode of operation?
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Yada, yada, yada. The computer doesn't control the tires nor take action if one goes flat. Your analogies are lame.
Pardon me if I don't put much stock in your interpretation of the FSM, the same interpretations that led to your "reset theory" in which the transmission pressure drops to zero at each shift and the transmission drops out of gear to "ease the strain on the gears".
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As are your explanations as to why my analogies don't fit. Oh, wait, you didn't bother to explain, guess that "explains" that, eh?

Well, you may not like it, but dropping the trans into two gear ratios at once is a bad thing, at least, so they tell me, not that I've ever seen any evidence of that (getting the sarcasm yet?). So I'm betting there was some though given to my theory when the trans was designed.
Have a nice day John, been good to hear from you. Same old same old it appears.
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The only simple fact that will emerge from this thread is that you, nor anyone else on this forum, knows exactly what is programmed into the PCM; if it is programmed to place the transmission in a certain mode when a certain failure occurs, the transmission is in an "operating mode" regardless of whether it's mentioned in the FSM.

Huh?
Not even a remote possibility since the designers of the TF used REAL hydraulic laws and theory and they could easily cite a source of that knowledge. So far the only offer of proof of your theories has been "It's so 'cause I say so". If you were so confident of your theories you'd cite credible sources of your "hydraulic laws" as I have challenged you to do on numerous occasions.

Yea, same old status in Maxworld where bullshit reigns.
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