General Motors Repair Technicians use a hand-held computer called the “Tech 2” to diagnose and tune modern vehicles. It is called the Tech 2 because there was originally a Tech 1, and this is the update.
Tech 2
The Tech 2 is like a scan tool on steroids, with some additional tuning options thrown in. As a scanning tool, the Tech 2 excels. While an off the shelf scanner will read the Engine Diagnostic Trouble Codes (DTCs), the Tech 2 will read and report information from all the car’s systems, including ABS, Air Conditioning, Air Bags, and other systems a standard scanner will not read. For example, in my CTS Seat experiment after the seat was replaced the Tech 2 must be used to run a Passenger Presence System relearn. There is no other way to run this tuning step other than with the Tech 2. Similarly some vehicle customizations or radio resets require a Tech 2 to perform.
Bosch has this informative video on the Tech 2: Bosch Tech 2 Video
Vetronix made the Tech 1. The original GM Tech 2 was made by Hewlett Packard and used Vetronix software. Vetronix purchased the Tech 2 manufacturing rights from HP. In 2003, Vetronix was acquired by ETAS, a supplier of standardized development and diagnostic tools for electronic control units. In 2006, the Vetronix Aftermarket division merged with Bosch Automotive Aftermarket, responsible for supply, sales and logistics of automotive parts for service of the vehicle. So today the Tech 2 is ‘made’ by Bosch.
The Tech 2 is used for GM Vehicles from 1992-present. It is kept up to date by updating the 32 MB Pcmcia memory card with the latest diagnostic software. Current cars with the CAN bus require the CANDI interface for the Tech II to communicate with the vehicle.
A Tech 2 costs — pick a number. New models appear to cost as much as $4K, and the retail price is shown as even higher — as much as $8K or $9K depending on the site. Discount new units are available for as low as $2300 on ebay for example, and used units run a bit less. There appears to be a market in Chinese clones for the Tech 2 and software, although I am opposed to piracy of intellectual property. My impression from shopping is that you should budget around $2K for an authentic Tech 2 in good condition with all accessories, 32 MB card, and CANDI module.
In the future GM appears to be moving to a laptop based scanning and diagnostic tool using the GM Multiple Diagnostic Interface (MDI) EL-47955. The GM MDI will replace the Tech 2 for diagnostics in the future, but will not replace the Tech 2 for 1992-2009 vehicles.
The GM MDI is a compact communication module that manages the transfer of data between a vehicles onboard ECU network and a PC. The GM MDI offers faster programming speed at a lower cost. Depending on the vehicle architecture, the MDI can be 20%-70% faster than the Tech2. The GM MDI allows the user to perform Pass-Thru programming procedures using software running on a laptop or desktop PC. Any PC can be used.