OBD1 ABS Power Brake Bleed - Kelsey Hayes 4wal - Snap-on MT2500

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hatzie

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The MT2500 & MTG2500 are great for reading live data from the 1991 & earlier GM rigs.
If I was buying a tool to talk to a 1992 and later I would get a Tech 2 clone with the NAO 33.004 Linear Flash card.
I would highly recommend getting four or five extra linear flash cards and a 3 or 4 working XP era laptops from Dell, HP, or Toshiba with PCMCIA and DB9 Male RS232 ports and rebuildable NI-MH or LI-Ion batteries. The Dell Latitude 820/830 fit the bill nicely. I have an Old HP and Toshiba that are less common but work pretty decent as well.

The Tech2 clone will work back to 1992 and maybe 1991 with the GM NAO 33.004 flash card. You can burn different binaries to the linear flash cards with a Windows XP or 2000 laptop with a PCMCIA slot and a pirate copy of Memory Card Explorer. My Old Toshiba Satellite, HP NX7400, and Dell 830 laptops work quite well. The Toshiba and the Dell have RS232 ports built in. I have no issues hoisting the Jolly Roger with long obsolete abandonware like MCE.

Aftermarket ABS support for these mid 90's GMT400 rigs is dicey at best.

As far as the MT2500 goes. I have one and it works quite well on ALDL and EEC III & IV era rigs.
One of your issues with the MT2500 could be, and likely is, because you're using two "primary" cartridges. I'm honestly surprised it boots. You're supposed to run one primary and one troubleshooting cartridge or just a primary with an empty slot. You can put the carts in either slot. The tool doesn't care. My tool doesn't complain about using a 1999 Primary Domestic cartridge and 1995 Fast Track Domestic cartridge when I screw up and forget to swap in the 1999 Fast Track Domestic cart.

The MT25001099 1999 domestic primary (GM Chrysler Ford Jeep) cartridge may have some 1995 updates that aren't in the MT25001098 1998 primary. BTW 1999 are the last ROM carts with 1995 and prior support. The 2000 and later primary cartridges dropped support for 1995 and prior vehicles.

I don't own the red or black programmable carts so I can't speak about coverage but I would be very surprised if they support the pre 1996 stuff. No way in hell you're going to get direct from Snap On updates for them. If there's no pre-'96 support I'd evilbay the programmable cart. There are a plethora of better tools for 96 & later rigs.
Snap On has some bizarre abusive ex girlfriend type software update policies in comparison to higher end Autel, Launch, and the not-Snappy tool truck diag tools. Several months after the latest updates Snap On software is no longer available. I would never buy a new Snap On tool based on that poor support.

You can likely read the ROMs but I wouldn't guarantee it. I've never looked into what chips they used and whether there's an EEPROM or Flash equivalent.

The personality keys needed to execute various functions using the SAE J1962 adapter plugged into the modern diag jack, be it bastardized ALDL like your 1995 or OBDII like the 1996 & later, will differ depending on the cartridge year. There are some long obsolete personality key tables that a helpful soul published in the Snap On diag tool forums. You should only need a few not a raft of them. I have five keys that came with my MT2500 and only used two of those.
 
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hatzie

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One thought that came to mind this morning.

The 1994 & earlier 12 terminal ALDL rigs with ABS needed a special data adapter for MT2500 MTG2500 ABS functions.
GM-1 is the regular 12 terminal ALDL data adapter
GM-2 is 1981-82 five terminal ALDL
GM-3 is 12 terminal ALDL ABS adapter

Assuming you can get to the ABS bleed function in the 1999 domestic cartridge software menus. You'll want to pay careful attention to which personality key the tool is requesting for when you try to access the '95 ABS bleed function.

***EDIT***
I found a definite answer on the Snap On forums. The MT2500 MTG2500 do not support ABS bleeding.
OTC 3210 will do ABS bleed on the OBDII rigs. It's almost the same price as a Tech2 clone and doesn't support 1995 so that makes it a non-starter for me.
 
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Mindtriped

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What happened to 18wheeleddemon? I was looking forward to seeing what he figured out as I have a 1995 c1500 Suburban. Did the Tech 2 from China work?
 
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What happened to 18wheeleddemon? I was looking forward to seeing what he figured out as I have a 1995 c1500 Suburban. Did the Tech 2 from China work?
I apologize man, not trying to spread my drama but I had spine surgery in February and I'm just a month into recovery. Back on my feet like a snail. With that said, I have nothing good to report, in fact my patience on this project as ended. After reading your message I got wild hair and decided to plug in the Tech2 and poke around. And... no joy. Indeed there are functions starting from 1991 thru 2012 however, automated brake bleed isn't an option for K series until 1998 is selected. Which is OBD2 - redundant. I've seen the Tech2 YouTube videos and it's ALWAYS an OBD2 vehicle, NEVER a OBD1. This does really jerk my chain because this Tech2 has ALL the other functions. You can literally and figuratively play Fast & the Furious computer modification games with this Tech2. Adjust idle speed, trim fuel pressure, SRS air bags, you name it... advance or retard the timing... all those functions are available but the ABS... all you get is a fluid level check, and codes and software information directly from the Kelly Hayes 4WAL. I'm just gonna eliminate the ABS. I've seen kits for other vehicles, I hope there's one available for our trucks. I'm done spending hundreds upon hundreds of dollars on scanner units then told, oh must be this or that or the other. I'm not gonna tell anyone what they should do but when it comes to ABS OBD1, I suggest eliminating it. Nobody seems to have any issues (or at least not as many with OBD1) with OBD2 ABS systems. I am not trying to be a jerk by any means, after so much research, thousands of dollars spent, nobody would be happy.
 
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One thought that came to mind this morning.

The 1994 & earlier 12 terminal ALDL rigs with ABS needed a special data adapter for MT2500 MTG2500 ABS functions.
GM-1 is the regular 12 terminal ALDL data adapter
GM-2 is 1981-82 five terminal ALDL
GM-3 is 12 terminal ALDL ABS adapter

Assuming you can get to the ABS bleed function in the 1999 domestic cartridge software menus. You'll want to pay careful attention to which personality key the tool is requesting for when you try to access the '95 ABS bleed function.

***EDIT***
I found a definite answer on the Snap On forums. The MT2500 MTG2500 do not support ABS bleeding.
OTC 3210 will do ABS bleed on the OBDII rigs. It's almost the same price as a Tech2 clone and doesn't support 1995 so that makes it a non-starter for me.
Well, your answer explains a lot and I'm not being sarcastic. When I bought the MT2500, I sourced every single adapter available for it. I have both plugs that are compatible however, no joy. Additionally, I have all the personality keys, I've tried them all just for kicks and giggles, no joy. We can officially say the MT2500 is useless for us when it comes to OBD1 ABS brake bleeding
 
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The MT2500 & MTG2500 are great for reading live data from the 1991 & earlier GM rigs.
If I was buying a tool to talk to a 1992 and later I would get a Tech 2 clone with the NAO 33.004 Linear Flash card.
I would highly recommend getting four or five extra linear flash cards and a 3 or 4 working XP era laptops from Dell, HP, or Toshiba with PCMCIA and DB9 Male RS232 ports and rebuildable NI-MH or LI-Ion batteries. The Dell Latitude 820/830 fit the bill nicely. I have an Old HP and Toshiba that are less common but work pretty decent as well.

The Tech2 clone will work back to 1992 and maybe 1991 with the GM NAO 33.004 flash card. You can burn different binaries to the linear flash cards with a Windows XP or 2000 laptop with a PCMCIA slot and a pirate copy of Memory Card Explorer. My Old Toshiba Satellite, HP NX7400, and Dell 830 laptops work quite well. The Toshiba and the Dell have RS232 ports built in. I have no issues hoisting the Jolly Roger with long obsolete abandonware like MCE.

Aftermarket ABS support for these mid 90's GMT400 rigs is dicey at best.

As far as the MT2500 goes. I have one and it works quite well on ALDL and EEC III & IV era rigs.
One of your issues with the MT2500 could be, and likely is, because you're using two "primary" cartridges. I'm honestly surprised it boots. You're supposed to run one primary and one troubleshooting cartridge or just a primary with an empty slot. You can put the carts in either slot. The tool doesn't care. My tool doesn't complain about using a 1999 Primary Domestic cartridge and 1995 Fast Track Domestic cartridge when I screw up and forget to swap in the 1999 Fast Track Domestic cart.

The MT25001099 1999 domestic primary (GM Chrysler Ford Jeep) cartridge may have some 1995 updates that aren't in the MT25001098 1998 primary. BTW 1999 are the last ROM carts with 1995 and prior support. The 2000 and later primary cartridges dropped support for 1995 and prior vehicles.

I don't own the red or black programmable carts so I can't speak about coverage but I would be very surprised if they support the pre 1996 stuff. No way in hell you're going to get direct from Snap On updates for them. If there's no pre-'96 support I'd evilbay the programmable cart. There are a plethora of better tools for 96 & later rigs.
Snap On has some bizarre abusive ex girlfriend type software update policies in comparison to higher end Autel, Launch, and the not-Snappy tool truck diag tools. Several months after the latest updates Snap On software is no longer available. I would never buy a new Snap On tool based on that poor support.

You can likely read the ROMs but I wouldn't guarantee it. I've never looked into what chips they used and whether there's an EEPROM or Flash equivalent.

The personality keys needed to execute various functions using the SAE J1962 adapter plugged into the modern diag jack, be it bastardized ALDL like your 1995 or OBDII like the 1996 & later, will differ depending on the cartridge year. There are some long obsolete personality key tables that a helpful soul published in the Snap On diag tool forums. You should only need a few not a raft of them. I have five keys that came with my MT2500 and only used two of those.
Reading your LONG reply, I am legacy PC hobbyist and with that said, I have said older equipment available. But as you mentioned, this would be a dicey effort. Sounds like more monkey business with zero actual progression. Here's my question: if the Tech2 unit, as is, will manipulate everything else, idle speed, fuel pressure, timing, ETC, why the heck won't it communicate with the ABS functions? What was the point of putting all that software and ability into it and leave out one of the most crucial functions. Calipers, boosters, and many other components get replaced all the time on vehicles, which will always require a full brake bleed procedure that requires purging air from the ABS pump as well.
 

hatzie

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Reading your LONG reply, I am legacy PC hobbyist and with that said, I have said older equipment available. But as you mentioned, this would be a dicey effort. Sounds like more monkey business with zero actual progression. Here's my question: if the Tech2 unit, as is, will manipulate everything else, idle speed, fuel pressure, timing, ETC, why the heck won't it communicate with the ABS functions? What was the point of putting all that software and ability into it and leave out one of the most crucial functions. Calipers, boosters, and many other components get replaced all the time on vehicles, which will always require a full brake bleed procedure that requires purging air from the ABS pump as well.
The Tech2 will talk to the ABS and every other system on your GM, SAAB, Suzuki, Isuzu, ...
As long as the PCMCIA binary is available and you have the ability to burn a PCMCIA card from the Binaries.

If the Tech2 will not initiate an ABS bleed function on a particular controller then that function is not available on that controller. I have the fuse removed from the ABS on my 2000 C2500 and I've disabled the ABS warning lamp in the instrument panel. I don't like how the brakes tend to randomly completely disappear on dirt roads and rough condition paved roads with it enabled.
 
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The Tech2 will talk to the ABS and every other system on your GM, SAAB, Suzuki, Isuzu, ...
As long as the PCMCIA binary is available and you have the ability to burn a PCMCIA card from the Binaries.

If the Tech2 will not initiate an ABS bleed function on a particular controller then that function is not available on that controller. I have the fuse removed from the ABS on my 2000 C2500 and I've disabled the ABS warning lamp in the instrument panel. I don't like how the brakes tend to randomly completely disappear on dirt roads and rough condition paved roads with it enabled.
I have no fuses pulled or anything as of yet disabled. So once again, I have the wrong software installed on the cart. I'll be happy to re-write the cart if that's all it is. I mentioned before, 1998 was the first year the bleed was available but in the YouTube video the guy had a 1997. He had a diesel so I'm unsure if that made any difference. I still find it amazing how every function you can think of is available except for ABS brake bleed.
 

hatzie

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The Diesels were odd critters.
I had a 1995 K2500 with the 6.5L Turbodiesel til I bought my 2000 C2500. The ONLY tool I ever successfully used to talk to that truck was my Tech2 Clone. The Diesel forums had some commentary at the time about how problematic the 1993-1995 6.5L ECM were to interrogate. IIRC 1996 was not noted to be a lot better. I didn't have my Red Brick or MODIS at that point but I question whether they would've talked to my orphan.

Ask your buddy what software bundle rev he has on his black primary cartridge.
Writing one of the black MT2500 cartridges could be a challenge if it's possible at all. You could end up with a very expensive bricked black cartridge. The tool trucks used proprietary scan bay hardware to write those black cartridges. The internals are BGA and several very fine pitch SMT chips. I don't have big enough balls to try doing this.

The information on the web is maddening cuz there's a bunch of contradictory information out there. :mad:

The Snappy forums claim that none of the MT2500 can do ABS bleed cause it was not enabled by the final Rev 9.2 bundle.

Your buddy was able to do it with his red brick and the procedure sounds right so that source is suspect.

I found this article from a 2007 trade journal that claims it was enabled for all tools supported in the spring of 2007. Specifically software bundle 7.2 and later.

I know proof positive that my Rev 6.4 black cartridges DO NOT do ABS bleed on anything but that is all I am able to definitively say.

Your MT2500 cabling, diag adapters, and personality keys are fully compatible with the MODIS EEMS300, Solus EESC310, & Solus Pro EESC316 so you could buy one of those bare if you want to go down that rabbithole.
All three of those will talk to ECMs from 1980 to the year prior to the bundle rev. Bundle 15.2 will talk to 1980-2014, 16.2 1980-2015 ...
The final bundle revs are as follows.
-MT2500 is 9.2
-Solus 310 is 15.2
-MODIS 300 is 16.2
-Solus Pro 316 is 17.2 ****NOTE**** There are rumors of problems with the 17.2 update on the Solus Pro. I would avoid anything newer than bundle 16.2

What rev is the PCMCIA card in your Tech2?
The final GM North American Operations card for the Tech2 is Rev. 33.004
There are at least two other binary files that could be tested on your Tech2. Look in the archive on Tech2WiKi.com
I would get a spare 32mb PCMCIA linear flash card rather than use your working golden asset. I have several cause I expect they'll be unavailable in a few years.
I have hard plastic PCMCIA memory card Jewel cases to protect em from impact damage and I put them in a Ziploc freezer bag to protect the cards from moisture. https://www.ebay.com/itm/272438096866
 
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The Diesels were odd critters.
I had a 1995 K2500 with the 6.5L Turbodiesel til I bought my 2000 C2500. The ONLY tool I ever successfully used to talk to that truck was my Tech2 Clone. The Diesel forums had some commentary at the time about how problematic the 1993-1995 6.5L ECM were to interrogate. IIRC 1996 was not noted to be a lot better. I didn't have my Red Brick or MODIS at that point but I question whether they would've talked to my orphan.

Ask your buddy what software bundle rev he has on his black primary cartridge.
Writing one of the black MT2500 cartridges could be a challenge if it's possible at all. You could end up with a very expensive bricked black cartridge. The tool trucks used proprietary scan bay hardware to write those black cartridges. The internals are BGA and several very fine pitch SMT chips. I don't have big enough balls to try doing this.

The information on the web is maddening cuz there's a bunch of contradictory information out there. :mad:

The Snappy forums claim that none of the MT2500 can do ABS bleed cause it was not enabled by the final Rev 9.2 bundle.

Your buddy was able to do it with his red brick and the procedure sounds right so that source is suspect.

I found this article from a 2007 trade journal that claims it was enabled for all tools supported in the spring of 2007. Specifically software bundle 7.2 and later.

I know proof positive that my Rev 6.4 black cartridges DO NOT do ABS bleed on anything but that is all I am able to definitively say.

Your MT2500 cabling, diag adapters, and personality keys are fully compatible with the MODIS EEMS300, Solus EESC310, & Solus Pro EESC316 so you could buy one of those bare if you want to go down that rabbithole.
All three of those will talk to ECMs from 1980 to the year prior to the bundle rev. Bundle 15.2 will talk to 1980-2014, 16.2 1980-2015 ...
The final bundle revs are as follows.
-MT2500 is 9.2
-Solus 310 is 15.2
-MODIS 300 is 16.2
-Solus Pro 316 is 17.2 ****NOTE**** There are rumors of problems with the 17.2 update on the Solus Pro. I would avoid anything newer than bundle 16.2

What rev is the PCMCIA card in your Tech2?
The final GM North American Operations card for the Tech2 is Rev. 33.004
There are at least two other binary files that could be tested on your Tech2. Look in the archive on Tech2WiKi.com
I would get a spare 32mb PCMCIA linear flash card rather than use your working golden asset. I have several cause I expect they'll be unavailable in a few years.
I have hard plastic PCMCIA memory card Jewel cases to protect em from impact damage and I put them in a Ziploc freezer bag to protect the cards from moisture. https://www.ebay.com/itm/272438096866
I am not interested in exploring that particular rabbit hole (MT2500). Additionally, "he" is not my buddy, he is a scalper mechanic I've already told off. I will never be able to see what software version his MT2500 CART has. Besides, the MT2500 is not beneficial (in my opinion) due to obscurity and price. Both are not in anyone's favor. In fact, I am thinking of selling off my MT2500 along with everything sourced for it. Although it too will not go cheap. I have well over $1k invested in it and please do not even breathe eBay... just so they can rob 50% of the sale and hold the money until THEY feel like releasing it, with a yet another fee fo fom fee. With all that said, I am interested in getting this Tech2 issue solved because they are not obscure and can be obtained for around $300 directly out of China brand new. This is beneficial for everyone both in price and availability. I am going to take your advice and wait on programming until I can source another flash cart for the Tech2. I'll eBay a couple of them. eBay... buyers heaven, sellers hell. Attached are images of the software versions I have for my Tech2. Lastly, I will share the link for purchasing the Tech2 beside this reply for anyone interested.
 

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