Need help on selecting GM MDI or Tech 2

Messages
363
Location
Va
For my 2002 GMC SUV as well as other mid 2000's GM vehicles, I'm ready to purchase either of the above mentioned. My thoughts are with a Tech 2, I have an all-in-one unit, but the MDI gives me options down tne road especially with our 2014 Toyota.

I'm fine with just a Tech 2 for the 2002 GMC for time being, but if I go with the MDI, would a regular Win 10 laptop work?

There are so many options I'm not sure where to start, mainly with options. I hear that some overseas sellers may not be the best choice due to customs.

I'm looking to try to stay under $500 for either setup if possible. Anyone who has been down this road, all input and criticism welcome.
 
Messages
25,789
Location
MA, Mittelfranken.de
Under $500 you are dealing with Chinese knock offs, some may be fine others not, they all use hacked software. The Tech 2 runs on Windows 7 although some say its works with 10 on a VM, I have never been able to get security access using a VM.
I cant recommend any one of them, I know people that have bought the Chicom ones and had problems with their information being stolen.

This is a MIDI 2 but it is more money and needs a subscription but it does work on Win 10. Watch a lot of you tube videos and only buy from vendors that accept PayPal. I would consider a good used Tech 2 or if a clone try to buy from a US seller so if anything goes wrong you have some hope of getting it taken care of, dealing with someone in China and sending it back and forth will burn up hundreds quick.

 
Messages
257
Location
Pennsylvania
As far as scan functions for your vehicle, tech2win is the software package, the MDI is the interface. Without a subscription the MDI is a nice looking paperweight. Global platform GM vehicles (starts with Camaro in 2010 and was all vehicles by 2014) use GDS2 with the MDI. Programming for any of the above is done with an SPS subscription and an interface. GM products that have a class 2 data bus (anything pre-can) does not program well with an MDI/MDI2 or modern J2534 device. Programming using the tech 2 as the interface is the only reliable way.

A handheld Tech 2 with candi module covers scan functionality on all GM from 1992 to 2009 and all non-global vehicles to 2013. New legit from Bosch they are in the 4500 ballpark and used around 2000. ANything cheaper is a chinese knockoff that may or may not work.

For scan only, there is no reason you need an MDI. A Cardaq M or Cardaq plus 3 works just fine and can also be used as an interface for Toyota Techstream for your toyota.

As far as a laptop. Win 10 is the only OS that GM supports anymore. Here is a link to the PC requirements https://gsi.ext.gm.com/userguides/Aftermarket Infrastructure Guideline v1.0.pdf
 
Messages
5,553
Location
Fort Worth, Texas
I have a couple friends using Chicom Tech 2's (Vetronix handheld knock-offs) & they seem to work just fine except for the Candi module dieing on one of them. YMMV!!!

I have one of the original Hewlett Packard Tech 2's that I bought through the Cadillac dealer I worked for in the late 90's & then had to purchase a Candi module in 2007 (Vetronix), I don't use it that often beside pass through duty, Unlocking radios, Or for some obscure module on a Cadillac.

My Snap-on Solus Ultra does almost everything a Tech2 will do & can't think of anything it won't do on a 2002 model besides be used as a pass through. I also have a Snap-on MT2500 "Brick" & does everything the Solus will do on Class 2 Serial GM vehicles, You just have to get the right cartridges.

The MT2500's can be found pretty cheap in pawn shops ($200-$300) with '05/'06/'07 updated programmable cartridges. You just gotta check that it has specific Domestic & Asian coverage & not just Generic OBD2 which is trash!

I'll probably catch some crap for mentioning a MT2500, But.....I've fixed thousands of vehicles with them & where the rubber meets the road it flat works!!
 
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15,773
Location
NE,Ohio
so I guess what we need to know is what you actually need to do with it that a decent
adapter such as OBDLink MX+ wont do.

as mentioned sky is the limit on these and subscription etc.
 

i6pwr

Thread starter
Messages
363
Location
Va
Thanks for the info.

My main goal at the moment will be for the 2002 Envoy and needing options such as a CASE relearn, clutch fan command, radio, security, ABS, anything transmission related.

Edit to add: HVAC actuators, any type of programming..pretty much anything I can control that cannot be done outside not having a Tech 2.
The OBD MX will let me watch fuel trims, O2 sensor data, etc, great for diagnosing.

I want to pick up a 2003-2006 Suburban at some point, so having full 2-way control is key.

We also have a 2014 Highlander which is why I was leaning towards the MDI 2 but I see now the I would be better off with the Tech 2 for my pre-2013 GM vehicles.
 
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Messages
5,553
Location
Fort Worth, Texas
A Snap-on MT2500 will do all that besides be a pass through, configure a module & unlock the radio. If I didn't own a shop......I wouldn't be concerned about Service Programming! It will NEVER pay for itself, It would be cheaper to have a mobile outfit come out & do it.

With your budget.....You're going to end up with Chicom knockoffs which I wouldn't trust for service programming duty anyway.
 

i6pwr

Thread starter
Messages
363
Location
Va
The MT2500 is surely an option, thank you. As far as the Tech 2 is concerned, I guess if I upped the budget to $1K-1,200, maybe more if it came to that, would this be something that needs a yearly subscription to maintain support or if I needed to add another VIN what kind of $$ are we talking to maintain proficiency?

Is GM discontinued any support on the Tech 2 with the advent of the MDI 2?

I guess if I could get all I needed with a Tech 2 for under $1500, that may be my best option.

As far as programming, another thought would be a possible idle RPM change, trans shift point or TCC lockup point. I assume these are possible?

Thanks again.
 
Messages
5,553
Location
Fort Worth, Texas
To change the calibration.....You will need HPtuners or EFILive, I use HPtuners & it's gotten cheaper now that you don't have to buy 8 credits with the interface.

GM only releases emission compliant calibrations & is not adjustable via a Tech 2 or MDI 2
 

i6pwr

Thread starter
Messages
363
Location
Va
To change the calibration.....You will need HPtuners or EFILive, I use HPtuners & it's gotten cheaper now that you don't have to buy 8 credits with the interface.

GM only releases emission compliant calibrations & is not adjustable via a Tech 2 or MDI 2

When we are talking "Changing calibrations", I'm assuming you are referring to changing fuel trims or fuel delivery, air/fuel ratios.. etc, which would be an emissions related area. Would setting a different idle RPM be considered an emissions calibration? Changing the RPM isn't my goal for the Tech 2, mainly other areas but have toyed with the idea.

That's good info about HP Tuners and the subscriptions.
 

i6pwr

Thread starter
Messages
363
Location
Va
A handheld Tech 2 with candi module covers scan functionality on all GM from 1992 to 2009 and all non-global vehicles to 2013.

Looking at a used Tech 2, if I have the candi module, is there anything else I would need or desire for 2000-2013 GM vehicles?

I see many with a large assortment of adapters and harnesses, honestly I don't know all I would need or use.

I'm comfortable with using it, just don't want to drop a grand on a used one, to find out I would need $500 in adapters amd wire harnesses.

Many I see have the handheld, the CAN module, and a connector. Also, many have a dozen connectors.

Forgive me for the basic questions, I'm new to the Tech 2 stuff but well-versed in diagnostics....just need the right tool. :)

Thanks
 
Messages
257
Location
Pennsylvania
Looking at a used Tech 2, if I have the candi module, is there anything else I would need or desire for 2000-2013 GM vehicles?

I see many with a large assortment of adapters and harnesses, honestly I don't know all I would need or use.

I'm comfortable with using it, just don't want to drop a grand on a used one, to find out I would need $500 in adapters amd wire harnesses.

Many I see have the handheld, the CAN module, and a connector. Also, many have a dozen connectors.

Forgive me for the basic questions, I'm new to the Tech 2 stuff but well-versed in diagnostics....just need the right tool. :)

Thanks
The biggest thing is the main unit, the cable, the candi module, the OBD II connector and the 32 meg memory card that holds the software. You can add different cards to add other manufacturers, like Saab, Isuzu and Suzuki. There are a few saturns that are on their own card, have never needed it. If you want to do any programming with it you will need an RJ45 cable and the RJ45 to RS232 adapter as well as a Keyspan USB to serial adapter. Again, only needed to program to connect the tech 2 to SPS. You would also need a power supply cord for the tech 2 for that. If you want to scan 92-95 cars you would need the OBD 1 12 pin adapter and the 12 volt power supply. for an OBD II vehicle the tech 2 powers off of the DLC. There is also a red adapter to program old saturns which I dont have. SOme other adapters for old Saabs, Suzukis and Isuzus. I never invested in anything other than the 12 pin OBD 1 adapter
 
Messages
5,553
Location
Fort Worth, Texas
When we are talking "Changing calibrations", I'm assuming you are referring to changing fuel trims or fuel delivery, air/fuel ratios.. etc, which would be an emissions related area. Would setting a different idle RPM be considered an emissions calibration? Changing the RPM isn't my goal for the Tech 2, mainly other areas but have toyed with the idea.

That's good info about HP Tuners and the subscriptions.

Anything outside of Tire Size & Final Drive Ratio changes is considered tampering & even then the choices are minimal.

HPtuners also comes with a pretty decent bi-directional scan tool & data logger......But it only covers powertrain, No ABS, Body, HVAC, or SRS support.
 

i6pwr

Thread starter
Messages
363
Location
Va
Anything outside of Tire Size & Final Drive Ratio changes is considered tampering & even then the choices are minimal.

Funny you mention that. Aside of regular HVAC, any sensor relearn, etc, I was also curious if bumping the idle speed up about 50 RPM could possibly improve the A/C performance while sitting in traffic, many GM vehicles suffer from poor A/C at idle.

That had me thinking if the RPM at idle had any stipulations with regards to idle emissions. I'm naturally curious if going to 650 RPM at idle would do anything, but I also want to play by the rules.
 
Messages
5,553
Location
Fort Worth, Texas
I would tweak the Fan Duty Cycle vs A/C Head Pressure table with a more aggressive ramp up vs kPa, You wan't some good airflow at approximately 1720 kPa (250psi).

TuNKiMy.png
 

i6pwr

Thread starter
Messages
363
Location
Va
I would tweak the Fan Duty Cycle vs A/C Head Pressure table with a more aggressive ramp up vs kPa, You wan't some good airflow at approximately 1720 kPa (250psi).

TuNKiMy.png

Ok, good info, thanks.

If I'm able to pick up an authentic Tech 2 used, will I need anything for it to communicate with my VIN? Will it basically be plug and play?
 
Messages
25,789
Location
MA, Mittelfranken.de
No, its plug and play deal, you can get a Candi module for $130 from Vertronix along with the GM card for $30.

 
Messages
5,553
Location
Fort Worth, Texas
Man....Those Candi Modules sure are cheaper than they used to be! Mine cost @$700! Technically, You don't need a Candi for a 2002 GMT360 or any GMT800 gasoline powered trucks.
 
Messages
257
Location
Pennsylvania
No, its plug and play deal, you can get a Candi module for $130 from Vertronix along with the GM card for $30.

Read the about on that page. Vetronix was bought by Bosch years ago. Thats simply a website selling knockoffs using the name
 

i6pwr

Thread starter
Messages
363
Location
Va
Read the about on that page. Vetronix was bought by Bosch years ago. Thats simply a website selling knockoffs using the name

That's one area that makes purchasing used models confusing. There are many Vektronix Tech 2's on the market used from $1k- almost 2K....are they genuine or chinese knockoffs?
 
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