What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

4l80E with 1993 diesel PCM

blasterD

blasterD

1/2 ton status
Joined
May 24, 2003
Posts
409
Reaction score
0
Location
Anchorage Alaska
I am planning to run a 4L80E in my 86 K30 diesel. I found a PCM from a 1993 Chevy K2500 diesel with a 4l80E. I have heard that this PCM can be used to control the 4L80E. Has anyone used this setup? If so, what sensors do you have to hook up to make it work? I assume that there would have to be a throttle position sensor and a vehicle speed sensor. Are there any other inputs to make the computer work? Can you use the 93 PCM wiring harness to hook it up?
 
the map sensor also is needed to tell the tranny if the engine is under load. If you do not mind shifting the tranny your self you could get a new valve body so you do not need a computer
 
Are you sure that a diesel truck would have a MAP sensor? I don't know for sure, but I wouldn't think that a diesel would produce much vaccuum to read with a MAP sensor. It was my understanding that a diesel PCM would judge engine load from the throttle position sensor. I also considered a manual valve body from Art Carr, but if I was going to shift I would just put in a NV4500.
 
I believe you are correct about the MAP sensor. You will need the VSS on the output of the transfer case, and there is a throttle position sensor on the IP that should be able to be adapted to your IP. I also think that you need an RPM sensor on the engine. Search on Ebay, I recently saw an auction that someone was selling all of the parts needed for this swap.
 
What is the PCM number? Been looking for info on a GM application that used the 4L80E "standalone", the PCM number would be a big help. Besides the fact you may find a bunch more info on how it "works" by searching the PCM number at places like the gmecm section of diy-efi.org.
 
I don't know the part number for the transmission PCM. I found this one while searching through car-part.com (my second favorite website). If you search for a 1993 Chevy 2500, click on transmission computer you will see a listing for transmission (diesel, right side under dash). I'm pretty sure this is the 4l80E controller. The cheapest one in my area is about $75 which is a lot cheaper than the TCI transmission controller that runs around $600. I remember reading on this site about 6-8 months ago of someone using this setup. I was hoping for someone who had worked out all of the bugs to point me in the right direction. Also, if someone has a 1993 diesel 2500 wiring diagram, maybe it would have some info.

Another option I have been considering is doing an ls1 6.0 swap like the blazer in Petersen's 4wheel & offroad. That way, the 6.0 ECM could be programed to run the 4l80E as well. Painless wiring makes a harness that lets you use the stock 6.0 ECM. I would rather get the transmission in and running before tackling the engine swap if it's possible.

Does anyone know if it is possible to hook up a vehicle speed sensor to a new style 205 transfer case? Otherwise, I will have to switch to a 90-92 NP241c.
 
Well, I can find the ECM number for diesel 4L80E applications, but I don't know enough about diesels to know which ones would require no ECM/PCM control.

Such as a 1991 6.2L 4L80E V3500. Does that powertrain combination require an ECM or PCM, or does it JUST need the transmission control? If someone can confirm that yes, the above vehicle does not need any sort of engine control from an ECM/PCM, then the ECM/PCM from that application should be useable to control a 4L80E with minimal hassle. At that point, the number of the ECM/PCM can probably be crossreferenced to find which vehicles will be donors.

A '90-91 GM 205 runs a VSS just like the 241, (which is 40 pulse per output shaft revolution) but that's the only source I'm aware of. I heard Dodge used a 205 later than GM, with VSS as well, but I could never find a definitive answer on that one.

Unfortunately there doesn't seem to be anyone that has done this, or those aftermarket transmission controllers wouldn't still be so pricey. It doesn't seem like we are very far off from figuring it out, only need the input from diesel truck guys as to how the engine management was handled when a diesel was coupled to the 4L80E early on.
 
Is the PCM easily programmable? Diesel engines need to upshift at MUCH lower RPM's than gas engines do. Seems to me that you need to program in new shift tables to get it to work right with a gas engine.
 
I do believe all of the early diesel trucks had a TCU that was stand alone from any sort of ECM. And yes, you do need to have it reprogrammed to be useable with a gasoline engine.
 
SierraClassic said:
I do believe all of the early diesel trucks had a TCU that was stand alone from any sort of ECM. And yes, you do need to have it reprogrammed to be useable with a gasoline engine.
Click to expand...

I thought about this...if they are a standalone unit, then that means that a DRAC was more than likely how the VSS from the tranny/t-case was handled, and how shifting was governed.

I would *think* though, that the shift points weren't solely vehicle speed governed...that would seem odd, I thought the electronic trannies were able to modulate the shift firmness based on engine RPM/throttle position as well, and that would require a few things a Diesel wouldn't need or have in most cases, like TPS and tach feed.

Maybe early 4L80E's were solely "speed shifters"? Something changed around 1992/93, as the ECM for the 4L80E application changed somewhere around then as well. The part number for a 1991 TBI 454/4L80E/205 V(?)3500 ECM is 16147060, which was NOT used on the 6.2's at all from the results here and wasn't used after 1993 for some reason.
 
OK this should do it for anyone looking to get started on this.

16147609 is the PCM for a diesel truck w/4L80E (MT1) from 1991-1993 mentioned as being a stand alone.

You can look up that PCM number here efi tune

Not a very common PCM if you can trust that site, only used those 3 years, and ONLY on diesel/4L80E apps. Probably not real common in wrecking yards.

Might be able to buy the PCM here (number is listed) critescore

Can't find any data on that PCM anywhere I know to look, but didn't spend a lot of time over at diy-efi.org...might have pinout in the message archives. Pinout should indicate what that PCM required to control the transmission.
 
1991-1993 GM electrical manual or some equivalent aftermarket manual will have the pinout of that PCM, now I think it just comes down to what all that PCM requires for input. Wiring should be no problem from a wrecking yard, just the PCM and whatever sensors it uses.

Could be completely pointless if it uses some kind of weird TPS that was modified to work with the diesels, etc.
 
I found a little more info over on the diesel page

http://www.thedieselpage.com/reviews/pcstrans.htm

It looks like I will need the following sensors:
TPS from a 92-93 6.5TD
VSS from a 91+ Transfer case
Engine speed sensor from a 92-93 6.5TD

So far I have been unable to find the ECM pinout listing for the computer. I am trying to find a 92-93 6.5TD at a salvage yard to look at the wiring. If I could get my hands on a service manual from a 93 6.5TD I think I would be good to go.
 
Check out www.helminc.com. They had the factory service manuals for pre 95 on sale for around $30.00 or so. That would give you the wiring diagrams you need as well as locations and installation of your new parts
 
blasterD said:
I am planning to run a 4L80E in my 86 K30 diesel. I found a PCM from a 1993 Chevy K2500 diesel with a 4l80E. I have heard that this PCM can be used to control the 4L80E. Has anyone used this setup? If so, what sensors do you have to hook up to make it work? I assume that there would have to be a throttle position sensor and a vehicle speed sensor. Are there any other inputs to make the computer work? Can you use the 93 PCM wiring harness to hook it up?
Click to expand...

You need the PCM, a TPS, and a ESS on the engine and VSS from transfer case. The engine VSS can either be a VSS only or one with a vacum pump/VSS combo. If you can find a np205 from a 91 K30 it should have the electronic hook up otherwise its a np241from 89-91. The pcm can also be found on many 6.5 NA p30 vans from about 91-95ish.Either way you will have to get the stock PCM reburned to match your tire and gearing combo. If i can think of anything else i will get back to you. I did alot of research on doing this same thing, i ended up getting a TCI unit.

there is no map sensor needed.
 
What sensors does the TCI unit use? I would guess you need some sort of VSS, and a TPS. Does it need an engine speed sensor as well? Also, does anyone know where to get the engine speed sensor for a 92-93 6.5? It is similar to the 6.2 vacuum pump. It goes in the hole where a distributor would go on a gas engine. It also has an oil pump drive on the bottom. I could probably find one at a salvage yard somewhere, but I can't find anyone who sells a new one. It might be a dealer only item.
 
The TCI unit uses the same inputs as the factory control control box. The biggest difference is that with the TCI unit you can adjust the programing yourself. Most of the sensors are dealer only items. I found all my parts on ebay.
 
ess signal

depending on your alternator ess can be tapped off the diode bridge. see a rebuilder some alts all it takes is a 6 buck plug. all the sense the 609 tcm needs is tps ess vss. and if you piggy backing it supply power to tps only from one computer . also the 4x4 uses vss front of trans rear trans vss not used. and output on transfer case used." jags that run" can fix you up for speed sensor for transfer case if you need to drive a cable speedo. and dakota electric has a cool box to control electronic speedometers cruise control etc. gm' drac is kind of a pain in the butt but it can be made to work to. prolly got all you questions worked out by now this is an old post lol. and im no expert on this subject i dont have a clue about the bling bling tci compushift etc. i just try to fool the the senses the 609 recives to manipulte the end result and its workin fine for me. for example would be alt pully larger = lower ess smaller=rippin rpm another example cable driven speed sensor same as above manipulate speedo gear. hey time = money as money=time. if ya want it now buy it. if ya like to get to the bones of it manipulate. it will be priceless when your broke down in nowhere and Courage is your only companion lol this ends my rant have fun.
 
What 4x4 uses VSS off the front of the trans? The 205 in my truck right now (1991 V3500, 454/4L80E/205) got/gets VSS off the transfercase output shaft which feeds cruise, ABS, speedo and ECM. (through the DRAC)

However, after wiring up the later electronic speedometer, unless there was an additional wire on the 1991 applications 4wd indicator light switch connector, the ECM has no way of knowing if the vehicle is in 4wd low, which would throw off the tranny. So a front mounted VSS could make some sense, but only if the ECM is programmed to compare VSS reading with what it is getting RPM-wise from the tranny, and just assume that if VSS readings double while the transmission internal speed is the same, it is in 4 low.

Or, is load somehow measured by a differential in output speed vs input speed, which seems extremely overcomplicated to me.
 
You must log in or register to reply here.

Latest Posts

Top Bottom