Security for a vehicle diagnoses port

A direct bypass straight to the battery (unfused) would be fun.

 

Depends how smart the tech is and what device they are using. On a nexiq 2, there is a light when you get power and ground at the diagnostic port. Cutting power or ground would have the same effect.
Putting one of the 1939 wires on a switch the the wire is open to the diagnostic port would make the appearencd of everything ok, but would not be able to hook up.
I know then hook up for speed limiters, not sure if they issue a ticket if the diagnostic port cannot be hooked up to.

On a side note, nothing pisses me off more then people hacking into the diagnostic plug with their own ########. If i cant hook up to a truck first thing is check power and ground, then rip the panel out and see what idiot butchered the wires on the backside.

 

Apparently no one knows how a control area network (can) communications works.

there is no ground use other than parisitic power for the can adapter in many cases.

 

And the first time you had to print a log page out at a scale they would know something was up.

 

If you really are worried about things that don’t happen, just move the real plug and put a dummy in the factory location.

 

Or they just take you to the dealer and have him repair the connection and you pay for that repair.
That is the next step.

 

This is what I use when on a rare occasion I have to take my truck to the dealership for some recall BS or something.
It locks the diagnostic plug so no one can make a mistake and update or reprogram the ECM with out my permission.

 

Can't help, I'm afraid.. There's BIG Fines here (& Grounding the Truck) for that sort of Thing Down here..