hatzie
I'm Awesome
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.
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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