Buying a used GM Tech 2

[lilcuda]

I recently purchased a 2013 Corvette and I would like to have a GM Tech 2 so I can run diagnostics when necessary. I actually may be having an issue with the Magnetic Ride Control shocks and I don't trust dealers to give me a straight answer. Anyway, I found a Tech 2 that appears to be an original GM one, but the seller says that it has the message "CANdi module not detected". I know the CANdi module is what allows communication between the car and the Tech 2, but what I really want to know is how do you fix that error. The seller sent me a link to the Vetronix site that has new modules for $139. Is it as simple as replacing the CANdi module?

Anyone have experience with these and dealing with this error?

Thanks.

 

[dnschmidt]

You failed to mention if you indeed have the Candi module. If you don't obviously it's not attached. You will need it for your Corvette so if you don't have it you're going to need to buy one.

 

[charbar]

Hard telling if its something with the Tech2 not recognizing the CANdi or the CANdi module itself I would say. Its been over ten years since I quit the GM dealer and have even been around a Tech2, but if I remember right the CANdi module just went in line between the DLC and the Tech2 with no additional wiring/power sources etc. So the chances that it actually IS the CANdi are pretty good I'd say. $139 for a CANdi module sounds super cheap to me.

I done ever recall seeing that error message on a Tech2 in all my years as a GM tech.

 

[Neggy]

I know the Snap on stuff will run actuator tests on each corner and re-program/re-learn the module, also has the system theory/operation available to read

 

[lilcuda]

You failed to mention if you indeed have the Candi module. If you don't obviously it's not attached. You will need it for your Corvette so if you don't have it you're going to need to buy one.

Well, I don’t own it yet. Considering buying it. The seller does have the Candi module, but he says it has the message on the Tech 2 about it not being detected.

 

[lilcuda]

Hard telling if its something with the Tech2 not recognizing the CANdi or the CANdi module itself I would say. Its been over ten years since I quit the GM dealer and have even been around a Tech2, but if I remember right the CANdi module just went in line between the DLC and the Tech2 with no additional wiring/power sources etc. So the chances that it actually IS the CANdi are pretty good I'd say. $139 for a CANdi module sounds super cheap to me.

I done ever recall seeing that error message on a Tech2 in all my years as a GM tech.

Yeah, that’s my concern. If it’s the Candi module, not a big deal, but if it’s the Tech 2, the whole thing is a paperweight.

 

[kbeefy]

There are alot of fake Tech II's around. Google it to see some of the tells.
Having said that, I had a fake one and it worked fine except for getting on the website for module programing.

 

[Walkers]

I sold my Tech II when I got my 2013 Silverado because it had very limited usefulness. I would look to aftermarket scan tools that do Bi-direction communication.

 

[PCMusicGuy]

Have you looked into the VXDiag modules? They are like an MDI clone and run a virtual tech 2 program inside of a virtual machine that most laptops can run.

 

[FMB4]

I wouldn't risk buying a scan tool with a known problem.

 

[Formula]

Seen that a million times. It’s usually a bad connection between the tech2 and the candi module (assuming the one you’re looking at has the candi module attached, it runs inline on the tech2). We would normally just unplug and then reconnect everything to get it working again. That, or the candi module is going bad. We’ve replaced a few over the years.

 

[charbar]

I sold my Tech II when I got my 2013 Silverado because it had very limited usefulness. I would look to aftermarket scan tools that do Bi-direction communication.

That is definitely something for the OP to consider. Why buy a tool that has basically been outdated for some time now?
Not saying the Tech2 is a paper weight by any means, but.....

 

[torqueman2002]

I retired from GM Powertrain in '13, and immediately missed having the OEM diag tools & service information.

In 2010, GM started phasing out the Tech 2 in favor of a laptop-based system called GDS2/MDI module.

I have found the Autel MS908 tool to be every bit the equal to the GM OEM tools - TECH 2/CANDi module, and the GDS/MDI module.

Plus the Autel covers many non-GM vehicles - domestic, European, and Asian. The first 12 months of updates are free.

 

[lilcuda]

Have you looked into the VXDiag modules? They are like an MDI clone and run a virtual tech 2 program inside of a virtual machine that most laptops can run.

Looked into those a bit. The software sounds like it is of questionable origin.

 

[lilcuda]

I retired from GM Powertrain in '13, and immediately missed having the OEM diag tools & service information.

In 2010, GM started phasing out the Tech 2 in favor of a laptop-based system called GDS2/MDI module.

I have found the Autel MS908 tool to be every bit the equal to the GM OEM tools - TECH 2/CANDi module, and the GDS/MDI module.

Plus the Autel covers many non-GM vehicles - domestic, European, and Asian. The first 12 months of updates are free.

Looked at those after you made the suggestion. Out of my price range. I’m a hobbyist, not a shop. Thanks for the suggestion, nonetheless.

 

[JSGAuto]

Looked into those a bit. The software sounds like it is of questionable origin.

I have one. It works, it is cheap.

The install was difficult, the support available was google. It took me several days to get it running on a separate machine. Due to the questionable software I wasn't running it on my normal laptop....which just adds more cost....I wouldn't recommend it unless you have patience.

 

[torqueman2002]

Yes, unfortunately the scan tools that can perform bi-directional controls, display OEM data accurately (even DTCs) tend to be north of $1,000. The affordable units tend to be glorified code readers.

The best way to to test a system/component is not to disturb the connector/pin/wire, unless absolutely required. That is where bi-directional control (ability to turn a component ON/OFF) separates the code reader from true scan tools.

The TECH2 was very capable during it's day, but the industry has moved on. While there are any number of clone (Chinese) TECH2s on the market, unlike the VETRONIX or Bosch sourced units, they are non-repairable due to the cost cutting internal components.

It was hard to justify the $$ when I bought for the AUTEL, but I had some AMAZON $$ that brought my cash layout down quite a bit.

The MS908 model has been discontinued, but the updated/enhanced replacement is so much better - the low and high speed can bus communication and display of modules would have been a God send when I was working on my daughter's 2004 Yukon Denali. I am so glad they traded that pile in.

Have you found any of the other scan tool threads helpful? There are a lot of members in your same situation; also, you may search Corvette specific forums for ideas.

Good luck.

Oh, if you know of anyone selling a VETRONIX TECH1, I'm interested. My AUTEL won't talk to my '84 Vette. LOL

 

[PCMusicGuy]

The TECH2 was very capable during it's day, but the industry has moved on. While there are any number of clone (Chinese) TECH2s on the market, unlike the VETRONIX or Bosch sourced units, they are non-repairable due to the cost cutting internal components.

The clones generally work very well. The largest failure with them is the power supply which is repairable.