How To Adjust Road Speed Limit On Mack Vision 2011 MP8 Engine?

I have a mack vision 2011 model with the MP8 red-painted engine, and I want to adjust the road speed limit to 100km/hr, but I can't communicate with the vehicle ECU.I tried connecting the ECU via my diagnostic scan tool, using VCADS Pro, but after connecting, and it was able to connect to the ECU, the following message popped up:the software installed on the engine is not compatible with the ECU software, therefore you won't be able to programme certain parameters.My Question:How do I go about this please because our drivers are ruining our business by going overspeed and violating the company standard, and so far, they have condemned two of this newly acquired mack trucks via accident due to overspeeding.That's why I want to limit their speed myself by adjusting the road speed limit on the trucks ECU without their knowledge.Is there any solution, or software that I would need to install on my computer to enable my diagnostic scan tool read from both the ECU and engine so that I can adjust the speed please?Thank you all in great anticipation.

 

Thank you Bulldog and cabwrecker, I do appreciate.But the problem here is that our local dealer here isn't that good with maintenance and servicing. They did worked on two, but those two still overspeed, and when I asked them, they said it does blah, blah, blah.Please if any of you know the exact software I can use to do this myself, it would be greatly appreciated.In case, I am a professional mechanical engineer, that's what I studied in the university, so I know my way when it comes to handling mechanical components and engines, all I need is just a head up and I am good to go.Again, I do carry out diagnosis of my other trucks myself using my diagnosis scan tool. I do diagnose my mack CH600, mack model 2000, 2004, mercedes benz and one of my chinese made truck with cummins engine.The only problem I am having right now is this Mack Vision 2011 with the MP8 red-painted engine.Someone must have worked on this particular mack truck, please kindly assist me and save me some sleeplessness nights pls.

 

@VolvoTech, I have bought the Volvo VCADS interface, and tried installing PTT on my laptop, but its not installing...some files failed to install, so the installation was not complete....please is there a solution?

What help can you render to me please don't hesitate. Thanks in anticipation of your good response soon.

 

I am using a windows XP OS...please can you direct me to a place I would download an updated version of the PTT software? Or can you send me a copy on negotiation? Thanks