Cloned tech 2 scan tool

[grasshopper645]

More interestingly, what protocol are missing on VXDIAG which won’t allow it to be used on pre 2007 Holdens?

Here is a pin out of OBD2 connector with its various protocol flavours

View attachment 224341

https://www.pinterest.com.au/pin/423549539957070190/?d=t&mt=login

If you open up the vxdiag unit, you will see pin9 does not have any printed traces going out to anything. So it's never going to work.

Also 2007 and before (approx) are NOT obd2, only the ECM is obd2 compliant. All of the communications are done on obd1 data bus. In fact, the ECM communicates to the rest of the modules over obd1. The PIM converts the packets from obd2 to obd1 to be sent to the rest of the modules (SDM, EBCM, ABS, etc)

Your obd2 diagrams in this post are not relevant as none of them are used. A tech2 unit connected to the obd2 port on a vz and prior holden is actually using GM uart (a Proprietary connection over ob1. Thats why none of your cheap bluetooth scan tools will be of any use to pull abs, airbag, or bcm related codes. Because they can't interface with the car at all.

If you can get one cheap enough, the vxdiag is ok as you can use it to interface with ecm functions and do bi-directional features like CPS relearn, actuate transmission solenoids, etc, but its definitely NOT worth spending money on them for the above reasons.

 

[grasshopper645]

And to go a step further...

The vxdiag uses a microprocessor ARM STM32F407 which is a cheap CAN-capable chip, however if you review the schematics for it it does not have any inputs for pin 9 lol, so its literally impossible to get this to work.

Now if i was blue-printing/designing the unit, i'd have used a STM32F413 which probably would work.

 

[Fu Manchu]

I was under the impression that early VZ were OBD2 and during production of the VZ transitioned to CANbus.

 

[krusing]

And to go a step further...

The vxdiag uses a microprocessor ARM STM32F407 which is a cheap CAN-capable chip, however if you review the schematics for it it does not have any inputs for pin 9 lol, so its literally impossible to get this to work.

Now if i was blue-printing/designing the unit, i'd have used a STM32F413 which probably would work.

Would it be hard to modify it to use PIN 9 ?
Could you use a Jumper wire ?

 

[Skylarking]

Would it be hard to modify it to use PIN 9 ?
Could you use a Jumper wire ?

I’d expect you’d need device firmware to make use of pin 9 and the diagnostics software application would also need to work with the protocols that are carried over the device hardware/firmware.

Put another way, if it was so easy it would have been done already

 

[grasshopper645]

Would it be hard to modify it to use PIN 9 ?
Could you use a Jumper wire ?

No you would need to de soldier the ARM processor from the board and soldier and programme a new one. Not viable.

 

[grasshopper645]

I was under the impression that early VZ were OBD2 and during production of the VZ transitioned to CANbus.

I don't know the exact timings on when the full systems were switched over but my 06 vz ute definitely has at least the cluster communicating over obd1.

 

[WickedGoat]

I was under the impression that early VZ were OBD2 and during production of the VZ transitioned to CANbus.

I can tell you that for the 2004-2006 GTOs, the 2004s were OBD2 and the 2005 and 6s were CANBUS. Don't know how that differs from the rest of the Holden offerings.

So after reading this thread, I am leaning heavily on a clone Tech 2 for my 2004 GTO and 2004 GMC Yukon. I am pretty sure it won't work on my 2014 Chevy Impala or 2016 GMC Acadia. What would you guys do?

 

[lmoengnr]

I can tell you that for the 2004-2006 GTOs, the 2004s were OBD2 and the 2005 and 6s were CANBUS. Don't know how that differs from the rest of the Holden offerings.

So after reading this thread, I am leaning heavily on a clone Tech 2 for my 2004 GTO and 2004 GMC Yukon. I am pretty sure it won't work on my 2014 Chevy Impala or 2016 GMC Acadia. What would you guys do?

A Tech 2 should work up until 2012. You'll need something compatible with GDS 2 for later models.