Proposal to UN-F37 our CRDs

warp2diesel · **Posted:** Fri Mar 21, 2008 5:02 pm

TurboTim & GMCTD: One of the F-37 flash characteristics is the undesired change in the shift points. I work with controls a lot and I have worked a bunch with Prox sensors and VFS that use frequency.
Here are the questions:
1) Does the TCM get a shared digital signal from the Speedometer pick up sensor so the TCM can tell when the trans to shift?
2) Does the Speedometer have it's own digital to analog converter to move the needle?
3) If this is true, wouldn't a change in the frequency sent to the TCM make it shift sooner or later?
4) Can an electronic trick box be constructed that would take the digital signal going from the Speedometer sending unit to the TCM and slightly raise or lower the frequency to redo the shift points?

Comment: Having adjustable shift points would be cool, right.

Steve

gmctd · **Posted:** Fri Mar 21, 2008 7:27 pm

Right, but, unfortunately, the speedo is no longer autonomous - ECM and\ or BCM drives the speedo, tach, fuel guage, oil pressure, ammeter, anything else in the instrument cluster - it is now a mere lackey to the host computer(s) - ABS, ECM, TCM, Cruise, ESP - everything does work off the speed sensors, but not like in my '96 - with the '98 advent of the 24v\VP44 system everything was handled centrally - made it sorta difficult to swap engines - now you need every hank of wire and every color size and shape module outta the donor vehicle, incl the instrument cluster, ash tray, cigarette lighter and cup holders - these ain't yer grampaw's Diesels, no more

The tech is available - what's needed is someone to really look into our limited venue - we're but a mere stink in the wind, compared to the big noise the Cummins and Hemi's make - ya gotta realize: this identical TCM has been used with the 45RFE and 545RFE with only minor software changes on Ram 1500\Dakota\Durango\Charger\DCJ 300\Jeep gassers (patooie!) from 1999 up thru 2004 - they then got a single-board computer which combined the TCM and ECM, called the PCM, or Powertrain Control Module - the KJ CRD has continued using this exact TCM since 2001 - Gran Cherokee has used it since 1999 - gasser (again with the lugie!) KJ's have also used it behind the V6 and small V8 - it ain't like we got a bastardized one-off scarce rarity, known only to Tibetan monks - we just got a standard-issue DCJ TCM CAN'ned to a small Diesel with Bosch EFI - they got TMR\EMCC, we got TMR\EMCC - 545 software is 545 software - what is the big deal?!?!?

The big deal is our small cash-register base - only about 5% of all KJ CRD's will be addressed by frustrated owners for upgrade goodies - only about 5% of Cummins and Hemi owners will not even be interested in upgrades and goodies - the squeaky wheel gets the grease, eh..................

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warp2diesel · **Posted:** Fri Mar 21, 2008 9:03 pm

There has to be one of three ways the ECM and the TCM talk: 1) Analog which is very unlikely I suspect the only Analog signal any more is going to the speakers. 2) Hi or Low voltage signals or 3) Digital communications in a pulse format.

PLCs talk with mostly Eithernet, Fiber Optic, blue hose, 4-20mA, or with old fashion hard wire Hi and Low signals. If the ECM tells the TCM when to shift, it must be sending a signal and the TCM is nothing but a dumb box with solid state relays. If the TCM is a smart box, it must be getting speed signals from somewhere off the bus so it knows when to shift. If so, all we need to do is tell it a little white lie to get it to shift at a better time if we cant crack the code in the ECM.

Steve

msilbernagel · **Posted:** Fri Mar 21, 2008 9:16 pm

Steve,

I think the ECM, TCM (and more) chat on the CAN bus, which is a published spec, but then they 'cheat' and don't follow the standard. They were sued by the government agency responsible for the OBD functions in autos (EPA?). They've improved it, but as makers of equipment like the ScanGauge have found, they still do funky things that 'break' software they've written. Most either indicate they don't support those dodge/chrysler products, or that some functions don't work. One thing they do, for example, is cause multiple master's to multiplex on the CAN bus (my recollection, anyhow).

I guess if you had the gear to do so, the thing to do would be to watch the system run and reverse enginer the chatter to understand how things work.

Mark
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warp2diesel wrote:

There has to be one of three ways the ECM and the TCM talk: 1) Analog which is very unlikely I suspect the only Analog signal any more is going to the speakers. 2) Hi or Low voltage signals or 3) Digital communications in a pulse format.

PLCs talk with mostly Eithernet, Fiber Optic, blue hose, 4-20mA, or with old fashion hard wire Hi and Low signals. If the ECM tells the TCM when to shift, it must be sending a signal and the TCM is nothing but a dumb box with solid state relays. If the TCM is a smart box, it must be getting speed signals from somewhere off the bus so it knows when to shift. If so, all we need to do is tell it a little white lie to get it to shift at a better time if we cant crack the code in the ECM.

Steve

gmctd · **Posted:** Fri Mar 21, 2008 9:28 pm

TCM is uprocessor, ECM is uprocessor, BCM is uprocessor, ABS is uprocessor, etc is uprocessor - they talk\respond on the 100kb high-speed differential serial digital CAN bus, and the 29kb medium low speed serial K bus - also the 10kb low speed DLC link bus - ECM and BCM and TCM are masters at various times, depending on function, with rest acting as slaves at those times - the transmission has been the same hardware since '99, requiring only a TCM reflash to go from 4sp to 5sp automatic - with minor changes in planetaries, it is now the 68RFE 6sp automatic behind the '07.5 6.7L Cummins engine in the Dodge trucks - again with a minor software change to shift 5 times instead of the previous 4 times, and the previously previous 3 times

Start out in first - shift 2 - shift 3 - shift 4

Start out in first - shift 2 - shift 3 - shift 4 - shift 5

Start out in first - shift 2 - shift 3 - shift 4 - shift 5 - shift 6

Alter the VSS input, and you'll get TCM, ABS, ECM and prolly BCM DTC for out of range - good thought, but these ain't yer grampaw's Diesels, unfortunately - it's gonna require a real professional hacker to get inside and do some hackin'

geordi · **Posted:** Fri Mar 21, 2008 11:58 pm

So again my question: If the Hemi guys are all using the same slushbox and TCM... Have their geeks broken the coding yet in the TCM? I'd be MORE than happy to go steal one out of a boneyard car, I think I could even find a suitable truck from the list you posted. But making it play nicely in my KJ... I wouldn't want the stealer to do ANYTHING like flashing it, as they would probably be stuck using the most-current flash, the F37. So someone else has to have this ability. Do you know anyone that does?

Donor TCMs could be plentiful for experimentation...

Magnum · **Posted:** Sat Mar 22, 2008 12:51 am

did only crd get f37 or did all get them?

gmctd · **Posted:** Sat Mar 22, 2008 2:32 am

I get that distinct impression from bits and pieces from vendors and Hemi truck\Charger clubs - need to join those to read any more, but they were concerned with TMRS and EMCC over there, also, several years back - would need to talk to them about F37\equiv

The TCM's are identical but for the flash - I've picked up a handful for open-casket investigation - however, you will need one flashed specifically for the CRD to prevent Bosch system DTC's - that's merely the difference in sensors'n'stuff used in the Diesel control system - the 545 routines will be the same, once you get past that

Turbo Tim · **Posted:** Sat Mar 22, 2008 11:34 am

I'm sniffin' around to see what else I can find out.
Supposedly there is someone in Texas that has a way to reprogram the TCM. Don't know if he has uncracked the code, or just written his own.
As soon as I hear something, I'll post.

MTB_TDI · **Posted:** Sun Mar 23, 2008 12:14 am

gmctd wrote:

The TCM's are identical but for the flash - I've picked up a handful for open-casket investigation - however, you will need one flashed specifically for the CRD to prevent Bosch system DTC's - that's merely the difference in sensors'n'stuff used in the Diesel control system - the 545 routines will be the same, once you get past that

What brand is the hardware inside the TCM? Motorola? (please say it is!) Kerma from the TDI club is starting to look at this as well. He wants to look inside the TCM to see what hardware it uses. I didn't have time to pull it and look inside it today. The wife was waiting and I was late anyway.

gmctd · **Posted:** Sun Mar 23, 2008 1:37 am

I am looking at a circle with an M inside it, so yeah - MC68HC11 be lookin' good.................

Tinman · **Joined:** Mon Apr 10, 2006 10:45 am **Posts:** 308

What about this?

http://www.powertraincontrolsolutions.c ... ent-4.html

I've thought about this for my 47re, but it's a little pricey for my needs.

gmctd · **Posted:** Sun Mar 23, 2008 5:54 pm

Way more than a little pricey - the 48RE just needs tc lockup, line pressure, and o\d control - that PCS TCU is full control for a modern auto trans that can't shift itself hydraulically - it would work very well here, but the KJ would need the Euro ECM flash for the manual trans to eliminate all the DTC's resulting from the missing DCJ TCM

MTB_TDI · **Posted:** Tue Mar 25, 2008 10:17 pm

Here is some info for you.

http://www.lostjeeps.com/forum/phpBB3/vie ... 692#316692

Proposal to UN-F37 our CRDs

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