Tedd

I've got a 27C512 chip with $0D program ID and a 16197427 ECM P/N. I loaded factory prom data onto Pocket Programmer 2 buffer then burned the info onto another prom. Now both proms give me a code 51 (Checksum fail). How do I disable the checksum on my config? I've read all the posts on this topic but they are for 165 ECM. I should have known this would happen!!!! I need this vehicle to go to work in the morning!!!

Thanks for any help you can give me:hail: :hail: :hail:

Tedd Edmondson
tedd319@swbell.net

Grumpy

BIG DISCLAIMER:

I have not in any way shape or form worked with this Mask.

But, at a glance it looks like 4008 would need set to AA to disable the checksum routine.

Can you do a file compare?.
The TunderCat file compare utility is great for stuff like this, FWIW.

Tedd

Thanks for your response Grumpy.

BIG DISCLAIMER:
I have not in any way shape or form worked with this Mask.
But, at a glance it looks like 4008 would need set to AA to disable the checksum routine.
Can you do a file compare?.
The TunderCat file compare utility is great for stuff like this, FWIW.

Well I haven't gotten to changing files in TunerCat yet, but, I did a Verify Device to the buffer data in Pocket Progremmer both on the original Prom and the newly burned prom. I'm trying to get the hang of programming before I start manipulating data. So my idea was, download the original bin file and burn it on a blank prom and smile extra big when i did it

Needless to say I'm not smiling at all
Now I get code 51 on Datamaster with both proms.

When I open the files in TunerCat I get graphs and data for all the parameters, constants and tables so I know I'm putting data on the new prom. But why would the original prom have a Checksum fail also?

When you say "looks like 4008 would need set to AA to disable the checksum routine" I understand that 4008 is a location and AA is a setting, but thats about all I know.

When I go to Edit Buffer in Pocket Programmer All I see is a column of addresses on the left (nothing close to 4008)and FF's in all the locations? Is this where I should find the 4008 location, am I even close on this?



Thanks Again !





:hail: :hail: :hail:

Grim Reaper

The Checksum by Pocket Programmer is not the same as GM. It won't work.

Tedd

Could you please elaborate Glenn? I've read in the archives that TunerCat automatically resets the Checksum, If I went into TunerCat and changed one parameter and then burned a new prom would that do away with the CheckSum failure?

How do i disable Checksum for the system I have?

Runs very poorly in limp mode

Thanks again for any advise ya'll can give me!

Tedd

Brent

iTrader: (1)

Have you disconnected the battery before retrying the stock prom?

You read the stock memcal/prom into the Pocket Prog using a header right? Seems odd that a stock memcal thats only been "read" would now give a code.

Maybe the PP ruined the the stock PROM somehow. I'm not familiar with the PP so its just a WAG.

Tunercat does automagically recalc checksum when you save a changed bin.

32V_DOHC

"But why would the original prom have a Checksum fail also?"

If you have never tried to burn to this PROM then the PROM has been corrupted by static or a misread. Go to GMECM to look for a good bin to replace the corrupted one.

HTH

John

Tedd

Yes it seems odd to me that the factory prom would change after just reading it! Yes I used a slightly modified 34 pin header to read the factory prom while still in the memcal, but I may have made a mistake and done something to the prom by not removing or inserting at the right time. I don't think I did but I'm not positive I didn't. I was aware of the procedure, but being my first time I may have made a mistake.

But the data from the factory prom and the newly burned prom both read in TunerCat graphs, switchs, constants and tables?

Right now I've disconnected the battery in the truck as you suggested and I'm erasing the newly burned prom so I can burn a new image on it only slightly modified in TunerCat (Raised fuel cut off speed) to see if it will solve the Checksum Fail code.

Thanks for your help, I'll let you know what happens when I connect the battery and try the reprogrammed prom.

:hail: all hail those who help lowley newbies:hail:

Tedd

Tedd

Where do I get a new bin for my configuration?

95 4WD Suburban auto GT4
I've got a 27C512 chip with $0D program ID and a 16197427 ECM P/N

I'd love to get a new bin to compare it with what I have!

Tedd

32V_DOHC

You can find a handfull of bins here

ftp://ftp.diy-efi.org/pub/gmecm/bin_...%200E%2031/0D/

You can check out there applications here

http://holman.cs.uml.edu/~sdurphey/bccfind/

HTH

John

Tedd

Well I unplugged the battery, LET IT SIT FOR 30 MINUTES and programmed a new prom, niether did any good! The factory prom and the newly TunerCat altered prom both remain in open loop with a code 51 shown in Datamaster. I must have done something to my factory prom

If anyone know where I can get a bin file for my configuration, let me know!!

I'm chasing down some leads from the posts above, but have yet an exact match (BCC=BJYL0099) I've found BJYM ? close enough?

Thanks for your help so far!!!!

:hail: :hail: :hail:


Tedd

Brent

iTrader: (1)

BJYM is listed for 2WD C1500's only. The transmission control parameters *might* be different from the 4WD K2500's. IE lower line pressures etc. I'd be hesitant to use the BJYM long term because of this.

That said, using BJYM to test your burning equipment/procedures would be acceptable IMHO. It should allow you to start and run the truck without a code 51.

If you can't find the BJYL online, maybe try asking on the GMECM @ www.diy-efi.org list if anyone has a copy (if you haven't already).

If that fails give a GM stealership a call and they can tell you if there are any supersessions to the BJYL. If one exists it may be online.

Tedd

I've got a BJYM bin. file downloaded and ready to program in a prom as soon as it is finished erasing.

I notice when in Pocket Programmer 2 there is a window for addressing the start of buffer, start of device and end of device. Should these start values be the same(i.e. 00000)? I seem to remeber a thread were someone suggested starting at 04000. This may or may not apply to my application.

While I'm at it, how long should I have to keep a prom in my UV eraser
(its a Spectroline, model PL-265T), I've been exposing the prom for 30 minutes, is that too long?

Thanks to all who help the lowly newbies:hail: :hail:


Tedd

Grim Reaper

The eproms generally need about 15 minutes the FIRST time and then you must slowly keep adding more time. I usually had to add 1 minute every 3rd or 4th write or it would trigger an SES code. BTW, these eprom have "memories'. If you start erasing 30 minutes, then they will usually need at LEAST 30 minutes and start taking more time.

What you SHOULD have done is read that initial BIN and saved it UNCHANGED to a file. That way if ANYTHING goes/went wrong, you could reburn it.

Alternatively, I recommend that you buy a second Memcal. Frankly, you should have a second memcal as a "backup" anyway.

Then you could read the BIN off the second one. And then reprogram the first one with the BIN from the second one. This is what I did when I started burning eproms. There was NO WAY I was ONLY going to have one Memcal. You NEVER know what can happen. I've burnt eproms that ran great for 15 minutes and THEN.....SES code and the engine ran like puke. Thank *** for the second Memcal.

Do that first, and then we can 'backstep" to see if there is something wrong with your eprom burning process (or whatever).

PS: No more bowing. If you REALLY feel like you have to thank us, send money.

Tedd

THE BJYM file that I downloaded, from a site 32V-DOHC suggested, Worked!!

I guess I did something wrong when I read the factory bin the first time. The program warns you what not to do. I may have did it

Glenn91L98GTA: wrote...
"What you SHOULD have done is read that initial BIN and saved it UNCHANGED to a file. That way if ANYTHING goes/went wrong, you could reburn it.
Alternatively, I recommend that you buy a second Memcal. Frankly, you should have a second memcal as a "backup" anyway.
Then you could read the BIN off the second one. And then reprogram the first one with the BIN from the second one."


That's exactly what I'll do. I was actually trying to do what you suggest in the first part of your quote, but, things went south with the first try.
This certainley boosts my confidence that this can work.

Do you think I could do any damage to the truck if Idrove it on the BJYM file? The BJYM file shows to be for a C1500,2WD,1/2 TON only and the same vehicle type is in the list of vehicles serviced by the BJYL file,
C1500,2WD,1/2 TON
C2500,2WD,3/4 TON
K1500,4WD,1/2 TON
K2500,4WD,3/4 TON

Like you said I need an extra memcal anyway so I can just get the correct file. What do those things run at a dealership$?

I still can't believe its working! Datamaster came on with all the graphs and showed closed loop!!!! It seemed like it ran better than with the original files! I took it out at midnite and gave it three dead stop to fuel shut off run's and she was smoother than she was before!
:lala: :lala: :lala:
I love the way my Moates ZIF adapter looks in place and workin!!!!

Thanks guys :hail:


Tedd Edmondson
tedd319@swbell.net

Brent

iTrader: (1)

Congrats!

Try emailing Dal @ Vandevere Olds for MEMCAL pricing. He'll surely do better than a local stealership. $50-$70ish

As far as the BJYM goes.... Without intimate knowledge of the tranny control routines and the 4L60E, its a crapshoot. Light duty driving probably won't cause trouble. I wouldn't tow anything. I tend to err on the side of cautious. A MEMCAL is leagues cheaper than a 4L60E.

Grumpy

I'm just curious about got fubar'd here, if you would send me a copy of the oem one that didn't work, and a copy of the one that did.

Try using AA at 4008, the engine should run fine,

Make sure you can repeat your results, once you get a spare memcal.

You want to get this dead nuts reliable.

nacelp@bright.net

No promises on when, thou

Tedd

I bought a factory memcal (BJYL) and downloaded the data and burned a factory BJYL prom that now proudley sits in mt Moates ZIF adapter. Now I need to try and successfully alter some fuel and spark tables for increased performance!!


I'm burning proms now!!

:lala: :lala: :lala:

Tedd