Being I have owned some of these units. Can offer some advice…
GM Tech 1, GM Tech 1a. Early and latter versions. Built and software by Vetronix. Petty much obsolite tool. GM coverage ended in 1997. ‘Valuable’ units would be with a GM MSC (mass storage cartridge thru 1997) or Global OBDII powertrain cartridge. MSC requires a VIM module for OBDII for 1994-1997.
I still have a Tech 1a with Global OBDII. Works on 2001 Cadillac, 2003 Saturn. Does not seem to work on 2005 Ford Mustang. Powertrain only.
Not worth much..
GM Tech 2. Info is correct about Hewlett Packard, Vetronix, and Bosch. Currently owned by Bosch.
There are GM logo versions, Saturn logo versions, MAC Tool, and OTC tool versions.
Early units used 10mb memory card. Current unit requires 32mb card. 2003 and newer require CAN adapter also know as a CANDI unit.
1996-1997. Ford and Chrysler software ‘was’ available.
Currently a GM ‘only’ tool. In 1996, it seemed like a very fast tool. Now, think 15 year old laptop.
Can access all systems. Air bag, abs, powertrian etc. Can program ‘welcome’ message on IPC etc.
GM Tech 2 cannot collect crash data from the air bag SDM. That requires a different tool: The Bosch CDR. The GM Tech 2 is considered a diagnostic tool, the Bosch CDR is considered a forenstic tool.
$8-9K for a GM Tech 2? There should be a law. In 1996 a new unit was $2600.
Bosch has a bulletin issued about fake China units. Stay away!
The real fire sale on GM Tech 2’s was about 6 months ago. GM went bankrupt. Thousand of GM dealers were closing…we bought 2 Tech 2’s from Saturn of Aurora for $1100 with 1 CANDI. One unit worked, one did not. Pretty good deal.
From the 2 units. We built one working ‘best of’ unit with CANDI. The other unit was parted out on eBay…paying for both. Great deal for us.
Be aware: Used dealership units are “played with hard and put away wet.” Pretty rough use.
IMO. EBay units are way overpriced. Your best bet is if a nearby GM or Saturn dealer is closing. Inquire about any Professional Diagnostic Tools Tech 2’s that may be available.
The only reason we found ours was from a different auction for a kent moore timing belt tool. We asked if they had any Tech 2’s. Uhhh…yeah we do..
Search for GM dealers closing shop. On eBay, search Kent Moore tools, J tools, AC tools, transmission tools etc. Hoists, tire changers etc.
As mentioned, 6 months ago there were some deals. My local Saturn dealer is, for now, still open. Many GM dealers may actually be able to hang on. What, maybe another 700 GM dealers get to stay on. That said, most that are closing, have closed.
Find the Pontiac, Saturn, Hummer dealers closing shop.