GL4 Chip

[DieselSlug]

I am going to be purchasing a heath GL4 chip for my 1994 Silverado. However i am going to be doing an engine swap with another 94 6.5 Vin f. I also have the computer to the new engine but am not sure if it works. I wanted to get the chip now to play around with it on the old engine, but they want the code on the back of the computer. Will the chip be okay if i put it into the computer that came with new new engine? I havent checked to see if the codes on the computers are the same. I want to use the new computer because it goes with the injection pump on the new engine. The injection pump isnt the special one out of a one ton. But i just kinda wanted to keep things together. And on the other hand i really dont know if the other computer is any good..... SO really i prolly should wait, what is your recommendations??

 

[buddy]

Please tell us the details of your truck, what model and engine type.

It should work no problem. I have swapped several PCMs into my engine with several different EPROMs.

And 94 PCM will be compatable in any 94, and some were installed in both 94 and 95.

If you get me the PCM part numbers and the EPROM codes I can give you more information.

The only real engine difference with the S and F engines are the precups. Then they added the extra EGR hardware. The EPROM program is different too, the main difference, but an F program will work in an S truck.

 

[DieselSlug]

VIN:F
Automatic Transmission.
GU6 Rear-3.42

 

[buddy]

So you have a C2500?

Got the "service #" of the PCMs and the EPROM codes on the top right of the PCM or listed on the EPROMs if you pop open the flap on the back? The EPROM code is also embedded in the number on the bottom of the PCM sticker. Should be 4 letters starting with B.. such as BMDN or BPXY...

 

[Ratman]

Mike, -welcome aboard! -Glad to see ya made it over here.

Like buddy said, with the '94, you shouldn't have any issues swapping ECM's, -and it shouldn't make any difference if you decide not to.

The EPROM between S and F are different, -but that's about it, -and they will interchange on the ECM no problem.

The '94 ECM(s) will also not care what DS4 is hooked up to it, -as long as it's not the special 5068 pump, -you're fine.

Welcome to DTR, -you're gonna like it here!

 

[DieselSlug]

Thanks guys, glad to be here. My truck is a k2500. IM contemplating on ordering one in the next week or so, just to see the improvement with my current engine. Kinda for giggles i guess. I will take a gander at the computers this weekend and post my findings. IM going to get doors, a tailgate, and tube steps tomorrow night and do the kodiak door handle thing, ive wanted to do that since i bought the truck. I might walk home with a few other things if he has good prices...lol Hopefully another few weeks and i can start on my new engine ratman.... I cant wait!!! Get my dads butt in gear so i can use his HD engine stand...

 

[JiFaire]

No, no, no.

The PCM (not to be confused with the ECM, for obvious reasons) does not just control the Engine. It controls the Powertrain. That includes shifting, TCC lockup, rpm limits, power curve for injection parameters, etc. Anybody who tells you it is only a few different parameters is blowing smoke at you. If I recall correctly, there are about 140 different settings to be programmed.

Incidentally, that's one of the ways you can tell a well-thought-out program from a hack job... the hack job just adds fuel and boost... the old Hypertechs or BDs were like that - lots of people cooked their engines with those.

What vehicle did you get the new engine out of? Was it a 1500, 2500, 3500? If it was a 2500, was it a K2500 or was it a C2500? What was the gear ratio of the differentials? Is it the same as yours? Was it a 4L80E transmission or a 5-spd?

The PCM is supposed to go with the truck; the engine, on the other hand, is fairly portable... you can put a 98 engine in your 94, even though the 98 was OBD-2 and the 94 is OBD-1... but your truck will need to keep the OBD-1 computer.

Watching out for the 5068 IP is only one of the things to be careful of.

Check to make sure the PCM RPO codes are the same; if you have questions, I strongly recommend you cann Bill Heath and ask him. Make sure you have all your data before you call.

 

[Acesneights1]

Listen to JF.
My 95 some idiot had swapped a PCM out of a 1 ton ambulance into My 1/2 Tahoe.Best part was the yellow Junkyard marking on it said 96 diesel whch would have been OBD2 anyway so who knows what it was. Tranny did weird things. Never shifted right. it took awhile of getting vin,pcm#, IP# etc before Bill Heath figured out what it was. He setup a V2 maxtorque that was right for my Tahoe. Aside from HP increase I noticed trans felt much much better. He was surprised it even ran. You need to talk to Bill.

 

[chrisk1500]

, I strongly recommend you cann Bill Heath

Bwahahaha....make sure he is wearing a cup before you kick though...I don't think he would appreciate being canned....


Sorry Jim.....couldn't resist....we all knew what you meant....

 

[JiFaire]

LOL... yeah, I can't type, Chris. I can't spell, either, so most of the time the two disabilities cancel each other out.

 

[buddy]

If you provide the numbers would be able to say if they are compatable, most likely are.

Many of the EPROM codes are diverse for C/K 2500/3500.

There have been updates to supercede some codes, so can tell you which is latest.

 

[Ratman]

Kennedy told me that ALL the parameters for the auto trans were there in '94 whether it actually had an auto or not.

Who can dispel this?

Obviously we're missing something. If the trans/lockup param's weren't there on some, -there would obviously be issues, -but that's not what I was told.

 

[buddy]

I can certainly say for sure that they arent in 95.

For 94s the Caldata software does give several codes for automatic tranny EPROMs when I specify Manual, mostly L49's with 4L60E and a few 4L80E, but not all of them. And it could be that someone input that data wrong.

 

[JiFaire]

The tuning tables are static. The DATA that they contain is not. If you have a GM EEPROM, you have a 'spot' (actually, several hundred spots) to put your Automatic transmission parameters... things like upshifts, downshifts, TCC lock, error handling parameters, etc, , but you may not have data in those spots. Or it may be the wrong data for your truck.

Iit's not as easy as it looks.. otherwise, any idiot could do it.

 

[DieselSlug]

The truck that the compueter came out of was a 1994 Silverado C2500. So it wsa a 2wd. And the engine has a automatic tranny flywheel on it, so te tranny must have been auto 4L80. Im not sure on the gears however.... I will pull my computer in a few minutes and get back to ya...

 

[DieselSlug]

Ok gotta type this fast, going to get some new body panels...... The computer that came with the new engine is BMSD. And the computer in my truck says BXRJ. Guess they are not the same. But the computer that came with the engine has a reman sticker on it........ Im confused be back late tonight....

 

[DieselSlug]

Here is the reman sticker off the computer that came with the new engine..

 

[mattthebrat]

Did you end up getting some doors yesterday?

Kind of like what Jim said I would just keep the PCM with the truck save yourself the work of swapping, the motors really don't know or care what they are hoked up to. And if you don't have a whole lot of info about the truck that the new PCM came out of, you could have a nightmare on your hands.

 

[buddy]

BMSD is an EPROM for that special high output 5068 IP, so that will not be compatable with the IP thats using BXRJ, 5067 or 5521 etc....

So if the new engine came with a BMSD chip and not an IP, then you dont need that chip. The PCM can be a spare though.

BXRJ is the latest and greatest available, released in 1996 with some updates, so it must have been updated in the past.

That PCM will work in any 94 truck.

 

[DieselSlug]

The new engine did come with an ip, so thats why i was going to change the computer. (so basically i do need the computer)? But i was wondering why the one that came with the new engine has a reman sticker on it, but supposedly isnt the newer one?? WHy is the original one that is in the truck now better?? It is older??