The Case for the Tech-2

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swathdiver

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The Case for the Tech-2


By J. A. Burns, Port Saint Lucie, Florida


I first learned the complete necessity of owning a scan tool designed for my given car at the dawn of the computerized automobile, owning and racing a stable of turbocharged Buick Regals. Even only being able to see and work with 20-40 sensor parameters proved crucial to keep our engines in top form.

Years later my wife and I bought a brand-new lemon from GM. That thing was in the shop all the time with gremlins that only the most dedicated mechanic could figure out. I wanted to buy a Tech-2 and work on it myself but they were too expensive at the time. When that one died, I budgeted a Tech-2 along with my next purchase of a GM product. It quickly paid for itself and keeps doing so. It’s the most important tool in my toolbox as it first determines which of my other tools, if any, will get used next!


So, what does this thing do? Well for starters, it can see everything! It can test almost everything. Have a misfire and want to turn off a coil pack or injector? Use the Tech-2. Alternator not working right? Power it up or down with the Tech-2. Are your catalytic converters acting up? Run a graph of the O2 sensors for a short drive and play it back when you return home. Hard to start? See that the fuel pump is at the commanded pressure. Air conditioning acting up? Use the Tech2 to check for codes and command the actuators back into position or a proper reset. It can also monitor the high and low pressures. Want to bleed your brakes thoroughly? The Tech-2 will bleed the ABS module correctly. It goes on and on and on. You can turn lights on and off, open and close windows and door locks, program tire pressures, enable Afterblow and see how many rpms the transmission is slipping and even how much torque the engine is making. You can see line pressures and even test the “valve body” or get a stuck piston unstuck; maybe! Same for the front axle and transfer case. Need to add some key fobs? The Tech-2 can do that too!

Of course, this machine cannot and should not be used by itself. It was designed to be used in conjunction with the shop manual which tells you how to use the Tech-2 and what to look for and do. That can be obtained via a subscription to AllDataDIY or one can buy the books on a disc or download them from SeriousCTBuyer on eBay. I like having both options and All Data is continually updated. The actual books are too expensive for me.

Another feature I didn’t even touch on yet is programming. Let’s say your instrument cluster fails and you buy a new or used one. It has to be programmed to your VIN (new) with the mileage and hours and this you can do yourself by buying access to GMs Tis2Web service. If you see that there’s an update for your transmission or you want to add side blind zone alert, you can do this without going to the dealership. If you change your engine from a 5.3 to a 6.2, you can program the computer for that but you cannot disable AFM. For that you’d need something like EFILive! or HPTuners. These aforementioned laptop-based products are for customizing your engine and transmission programs. I have yet to do any of this.

A quick word about generic code readers. These little Bluetooth ones that talk to an app on your phone are nice when you’re on the go. However, they do not always use the same codes to describe a problem that GM does. And most of them cannot talk to your ABS system or tell you why the heated seats stopped working. GM uses specific codes and for some items like the air actuators, provides symptom numbers which tell you why it failed, not just that it did. By the way, when the Yukon takes us on a trip, the Tech-2 goes with us!


The Tech-2 was made for use on autos from about 1991 through 2013 when it was replaced by the MDI later MDI 2 with GDS2 software running on a laptop. Quite unwieldly to use while driving. The Tech-2 can hang from the steering wheel. The final software update is 33.004 for North American autos and is stored on the included PCMCIA card.

Not all Tech-2s are or were made the same. OTC, Bosch and Vetronix are the companies that I know of that were licensed to produce and sell these for GM. Vetronix being the last, had them produced in China. These latter ones are missing some of the features of the earlier ones like the ability to copy PCMCIA cards and the training emulator. Not really necessary for the home user. People say there are clones made but I believe that the factory in China kept making them and started selling them on their own when GM moved to the other platform. Does that mean the Chicoms stole it or did they change the design 10% to avoid copywrite violations? I don’t know the answer to those questions. However, mine (circa 2017) looks identical to a Vetronix unit made in China in 2010.

These things come with a bunch of cords and adapters that most will use but once for self-testing the first time out. The Candi Module is not needed for GMT800s and earlier. It’s nice to have the various power adapters. Mine came with a bad OBDII adapter but once discovered, was promptly replaced. I bought the hard case made for it; keeps everything snug as a bug in a rug. Some ads say not for trucks. I can only think they mean the Kodiak/Top Kick and the White GMC types.

Often the Tech-2 will come with TIS2000 software. If your vehicle was made before 2009 or so then you would probably not have to use the pay to play Tis2Web service. A recorded data log can be downloaded to the laptop and played through this software, which makes it much easier to see all the parameters moving at once. Oh, and it can work with Windows 7 too. Some videos are posted on my YouTube channel.


The following is how the Tech-2 has benefited our family. Ever since buying the truck the gas mileage was off, not good. Even after having it tuned by BlackBear and having him disable AFM the mileage slowly got progressively worse. Finally, a code started popping up for a bad catalytic converter. People would swear it was the O2 sensors but the Tech-2 and shop manual teach you how to test those out. It was the catalyst. Then a few months later the other one went and the whole Y-pipe was replaced with a new one. To start out fresh, the Tech-2 was used to reset the Fuel Trims and Alcohol Content. The Tech-2 is also used to record the alcohol content of the fuel as it mostly runs on E85. Some gas stations are sneaky and put a wee bit too much ethanol in their gasoline.

During the summer I noticed that the driver’s side air wasn’t getting as cold as it used to. Tech2 showed a code and the reason why for the driver’s side actuator. For a year now, I have been able to command that actuator back into position and sync it, kicking the can down the road. After time, another actuator got stuck and the Tech-2 got it unstuck.

In the tire section, there are entries for the type of tire and air pressures run. My truck originally came with P-Metric tires with the air pressure set for 30 psi. Using the Tech-2, we told the truck’s computer that it is now wearing Load Range C LT tires at 50 psi. This means the low-pressure warning will now come on at 40 psi instead of 20.

The Tech-2 of course can see which TPMS sensors are at which wheel. This has exposed a tire store who said they rotated the tires when they didn’t! The new positions are written down after each rotation.

The truck came with a basic ACDelco silver battery. Watching the parameters in the Body Control Module, I can judge its health and watch the system carefully charge it up and shut down the alternator when it is fully charged, or at the point the computer wants it to be at.

One day a scan turned up a bad coax cable for OnStar. Phone still sounds good. Later on, sometimes, the OnStar light would be red for a few seconds and go green on its own or with the help of the Tech-2. About a year later my Bluetooth calls would sometimes get a lot of interference. The other coax had thrown a code. Sealing the shark fin antenna has helped a little. GM will get to do that repair, I’m not dropping the whole headliner to change those out! But at least I know what is wrong and how it needs to be fixed. No smoke and mirrors should get past me.


Well, I hope this post proves helpful and saves you and your family some money when it comes time for repairs and maintenance. I have no formal training with these and have probably only scratched the surface as to what they can do. I hope some GM Techs will chime in.


Did you know that the GMT-900s have an internal transmission oil life monitor that can be reset? Now, I bet you want to know what your oil’s life is, right? Get a Tech-2!

December 2018
 

shreksbrother

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Wow, thanks for that motivating write up. To be honest, the reason I haven't bought one yet is the confusion over exactly what I need to buy. Software/subscription/tool/etc.

Would you mind sharing what you found it necessary to buy?

Sent from my Galaxy Note9 using Tapatalk
 

SnowDrifter

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Reason's why I haven't gotten a tech 2 or MDI: I've read about the numerous issues with clones, both from a reliability and functionality perspective. And the difficulties in sorting clones vs. functional units.

Did you have any advice on seeking out a fully functioning unit?
 
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swathdiver

swathdiver

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Wow, thanks for that motivating write up. To be honest, the reason I haven't bought one yet is the confusion over exactly what I need to buy. Software/subscription/tool/etc.

Would you mind sharing what you found it necessary to buy?

Certainly. Most of the sales come with everything you need to use the machine to diagnose your auto. They come with an assortment of adapters that you'll never need as they are used for other cars. The most important thing is to make sure that the software version is 33.004. The wall wart to run the machine in the house and the other to coonect directly to a cigar lighter or battery are also important and necessary but seldom used. All the sales I've seen come standard with these accessories.

If one has a GMT-800 or other auto that does not have the CAN Bus system then they would not need the CANdi Module. Most sales come with it anyway.

Then there's the TIS2000 software and the USB key to make it work. I paid another couple dollars for the USB Key and installed the software on my laptop. I really don't know how to program modules yet but I have recorded data on the Tech2 and then connected it to my laptop to view it in the TIS2000 software. I don't remember having any installation issues but @Rocket Man did and he can tell you how he got it to work, his memory is better than mine!

Finally there's the case. It costs about $40 for the case that was made for this and I went ahead and bought it. Everything has a place and I like it. Others buy cases from Harbor Freight and cut out foam to fit everything for a lot less. To each his own.

https://www.youtube.com/channel/UCmZre5w_3lV_AOHxPkFGT7Q

Ohh, one more thing is needed. A connection from the Tech-2 to your laptop!

My 2006 vintage HP laptop computer needed an adapter to talk to the Tech-2 as it does not have a serial port. After much research, this is what works easy peasy, plug and play:

Tripp Lite Keyspan High-Speed USB to Serial Adapter, PC & Mac (USA-19HS):
https://www.amazon.com/gp/product/B0000VYJRY/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
 
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swathdiver

swathdiver

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Reason's why I haven't gotten a tech 2 or MDI: I've read about the numerous issues with clones, both from a reliability and functionality perspective. And the difficulties in sorting clones vs. functional units.

What issues of reliability and functionality have you found?
 

shreksbrother

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Certainly. Most of the sales come with everything you need to use the machine to diagnose your auto. They come with an assortment of adapters that you'll never need as they are used for other cars. The most important thing is to make sure that the software version is 33.004. The wall wart to run the machine in the house and the other to coonect directly to a cigar lighter or battery are also important and necessary but seldom used. All the sales I've seen come standard with these accessories.

If one has a GMT-800 or other auto that does not have the CAN Bus system then they would not need the CANdi Module. Most sales come with it anyway.

Then there's the TIS2000 software and the USB key to make it work. I paid another couple dollars for the USB Key and installed the software on my laptop. I really don't know how to program modules yet but I have recorded data on the Tech2 and then connected it to my laptop to view it in the TIS2000 software. I don't remember having any installation issues but @Rocket Man did and he can tell you how he got it to work, his memory is better than mine!

Finally there's the case. It costs about $40 for the case that was made for this and I went ahead and bought it. Everything has a place and I like it. Others buy cases from Harbor Freight and cut out foam to fit everything for a lot less. To each his own.

https://www.youtube.com/channel/UCmZre5w_3lV_AOHxPkFGT7Q
Thanks for the info. Reviewing your videos, I see lots of monitoring, but can you make changes, as well?

So would something like this work:

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/173679347695

Sent from my Galaxy Note9 using Tapatalk
 
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swathdiver

swathdiver

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Thanks for the info. Reviewing your videos, I see lots of monitoring, but can you make changes, as well?

So would something like this work:

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/173679347695

Sent from my Galaxy Note9 using Tapatalk

You can change many things as mentioned in the first post but you cannot disable AFM or increase your timing permanently for performance and things like that.

Yes, that sale has everything you'll need save for a place to keep it all together.
 

TJ Baker

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I bought a Tech 2 on Aliexpress last fall. Haven't done a whole lot with it beyond exploring and turning on my drivers side heated seat which otherwise won't stay on. I'll fix that some day. I might have bought service manuals in electronic form, can't say for certain. I only remember the purchase, but have never even looked at the CD/DVD!! Some day. I can warn against pressing buttons when you don't know what it will do. I was noodling about with the Tech 2 hooked up to my 02 Trailblazer and came across something like "Instant OAT calibration" . Figured that would calibrate my outside ambient air temp display. Pressed the button. My outside air temp now displays 40 below at all times!! I guess there is some other action to be taken before pressing that button!! Fortunately the engine has its own air temp sensors ;)
 

iamdub

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I spent over $200 on a top-of-the-line scan tool that reads all modules from ECM to TCM to ABS to SRS, etc. It'll graph live data for all or just user-selected systems. It can save info to be printed later. As capable as it may seem, it's still only a one-way tool and that REALLY makes it limited. Had I known for $75 more I could've had "the world at my fingertips", I certainly would've went that route without hesitation!

Thanks for writing this up and making a thread to populate all the latest pertinent info on this.

Mods: Sticky material?
 

Tonyrodz

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Great info James. I wish I had the extra $$ to get one. There's a used one for sale online. Guy says it needs to be updated. Have sn idea what updated discs cost?
 

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