Disabling the OBD Port for Free!

[Zafi]

Today I took out a fuse which allows the car to start, run, drive, stop etc as normal BUT the OBD port no longer works.

It's free, takes seconds to reverse if you are taking the car for a service etc and will mean the car cannot be stolen by breaking the drivers door glass and reaching in to access the OBD port

 

[Darren92]

Not sure why you deleted the previous thread but as I said, it won't stop them stealing the car, it will stall them for a few extra seconds but they'll have come prepared for scenarios like removed or blown fuses.

 

[Zafi]

But they have to unlock the deadlocked passenger door to access the fusebox without setting off the alarm.

I read of another method which involves putting 12v onto the K pins so it blows their device, but that's going a bit too far??

My experience with motorcycle thieves is they leave the scene asap if things are not straighforward and move onto another vehicle. This is even easier with cars as there are so many about.

 

[Chris90]

I looked at the fuse diagrams and the fuse powers some other modules in the dash. Hence why I havent recommended removing it until I can look at a new wiring diagram from 2009 onwards as thats where my etka stops.

 

[John@ECM-TECH]

Does anyone have these diagrams for the B8 (obd2, can etc)

 

[Chris90]

Will get my manuals working and post up the diagrams for the B8 and B8.5.

 

[Zafi]

Well, I have been driving about all over the place and everything works.

 

[Craig Norquay]

Care to share the fuse number so we can at least look into it Zafi?

 

[Zafi]

Yes, passenger side, left bank of fuses, second from top. It's a 10A fuse.
I popped the fuse out and put it in a vacant slot second from bottom

 

[Tosseef]

How about a latching relay circuit to the OBD live, so it's powered when YOU want it? Simple and effective. Done it loads.

 

[desertstorm]

Looking at Elsa Win there are 2 power fuses for the T16 diagnostic plug.
The wiring of the plug is here


The fuse locations on the passenger side.

ST2 fuse 11 is a 10A fuse and ST1 fuse 7 is a 5A fuse. These fuses seem to serve no other purpose than powering the diagnostic socket.

The 10A fuse is from terminal 30 so direct connection to the battery, the other 5A fuse is an ignition switched live.

 

[Dsport]

Yes, passenger side, left bank of fuses, second from top. It's a 10A fuse.
I popped the fuse out and put it in a vacant slot second from bottom

You'd be better popping a blown fuse in there

 

[Zafi]

Yeah, I will do that. Ta

 

[Zafi]

Looking at Elsa Win there are 2 power fuses for the T16 diagnostic plug.
The wiring of the plug is here
View attachment 91712

The fuse locations on the passenger side.

View attachment 91713

ST2 fuse 11 is a 10A fuse and ST1 fuse 7 is a 5A fuse. These fuses seem to serve no other purpose than powering the diagnostic socket.

The 10A fuse is from terminal 30 so direct connection to the battery, the other 5A fuse is an ignition switched live.

Yeah, same as the owners manual, that's why I took out the 10A fuse.

 

[Chris90]

Data bus diagnostic interface, Engine control unit
J217 - Automatic gearbox control unit
J533 - Data bus diagnostic interface
J623 - Engine control unit
J743 - Mechatronic unit for dual clutch gearbox
T17b - 17-pin connector, blue
T17r - 17-pin connector, white
T20d - 20-pin connector
T94 - 94-pin connector
B383 - Connection 1 (powertrain CAN bus, high), in main wiring harness
B390 - Connection 1 (powertrain CAN bus, low), in main wiring harness
D159 - Connection (high bus), in engine compartment wiring harness
D160 - Connection (low bus), in engine compartment wiring harness


Heres the wiring diagram for the port. Think a lad posted it above, but only a snippet of it. Does look to be different between the 2009 model and the later 2013 model.

Cant find a actual T16 connector for the plug so god knows whats going on there

 

[John@ECM-TECH]

Looking at Elsa Win there are 2 power fuses for the T16 diagnostic plug.
The wiring of the plug is here
View attachment 91712

The fuse locations on the passenger side.

View attachment 91713

ST2 fuse 11 is a 10A fuse and ST1 fuse 7 is a 5A fuse. These fuses seem to serve no other purpose than powering the diagnostic socket.

The 10A fuse is from terminal 30 so direct connection to the battery, the other 5A fuse is an ignition switched live.

Nice one, but you could just ground and power it from behind?

 

[Chris90]

In addition to my post above...Looks like the wiring is the same for 2012/13 onwards



Data bus diagnostic interface
J234 - Airbag control unit
J519 - Onboard supply control unit
J533 - Data bus diagnostic interface
ST1 - Fuse carrier 1
ST2 - Fuse carrier 2
SD7 - Fuse 7 on fuse holder D
SD11 - Fuse 11 on fuse holder D
T16 - 16-pin connector
T16b - 16-pin connector
T17b - 17-pin connector, blue
T17e - 17-pin connector, red
T20d - 20-pin connector
T100 - 100-pin connector
135 - Earth connection 2, in dash panel wiring harness
687 - Earth point 1, on centre tunnel
B383 - Connection 1 (powertrain CAN bus, high), in main wiring harness
B390 - Connection 1 (powertrain CAN bus, low), in main wiring harness
* - see applicable current flow diagram for airbag
*2 - see applicable current flow diagram for fuse assignment
*3 - see applicable current flow diagram for basic equipment
*4 - Diagnostic connection


So agreeing with desertstorm above.

Fuse 7 on Fuse holder 1
Fuse 11 on Fuse holder 2

Pictured the fuse diagrams too.


Should be a handy mod for people to do and saves against buying a OBD protector. As even if the thieves tool can bridge the Terminal 30 and Terminal 15 supplies to link the ignition live, its still not going to work as port is completely dead.

 

[ub7rm]

Very nice - what MY is your car Zafi?

 

[John@ECM-TECH]

all you need to to is strip the ign live and power it via the rear of the port, then it will work, also you could power the tool separately

 

[Chris90]

I guess it depends how long they are willing to mess about with trying to get the port to work. Most will probably just want a quick and easy plug in and press the button to code new keys. Not try get power to the ports.

 

[amafzal88]

In addition to my post above...Looks like the wiring is the same for 2012/13 onwards



Data bus diagnostic interface
J234 - Airbag control unit
J519 - Onboard supply control unit
J533 - Data bus diagnostic interface
ST1 - Fuse carrier 1
ST2 - Fuse carrier 2
SD7 - Fuse 7 on fuse holder D
SD11 - Fuse 11 on fuse holder D
T16 - 16-pin connector
T16b - 16-pin connector
T17b - 17-pin connector, blue
T17e - 17-pin connector, red
T20d - 20-pin connector
T100 - 100-pin connector
135 - Earth connection 2, in dash panel wiring harness
687 - Earth point 1, on centre tunnel
B383 - Connection 1 (powertrain CAN bus, high), in main wiring harness
B390 - Connection 1 (powertrain CAN bus, low), in main wiring harness
* - see applicable current flow diagram for airbag
*2 - see applicable current flow diagram for fuse assignment
*3 - see applicable current flow diagram for basic equipment
*4 - Diagnostic connection


So agreeing with desertstorm above.

Fuse 7 on Fuse holder 1
Fuse 11 on Fuse holder 2

Pictured the fuse diagrams too.


Should be a handy mod for people to do and saves against buying a OBD protector. As even if the thieves tool can bridge the Terminal 30 and Terminal 15 supplies to link the ignition live, its still not going to work as port is completely dead.

So do you remove both fuses to keep it secure?

 

[Chris90]

I would personally.

 

[feva]

I would personally.

You removed both fuses from yours Chris? With no adverse effects?
Mines the same sort of age as yours.

Sent from my Note 4 using tapatalk

 

[Chris90]

Havent yet. But might do when I get round to it ( one of those types of jobs)

 

[xpoweruk]

Quick question

Is it possible to remove a fuse that cuts power only when the ignition is off?
The reason being my P3cars gauge uses the OBD port when the ignition is on

 

[Chris90]

Fuse 11, is constant feed from the battery.

I imagine tour P3cars device will need both the fuses to work....but its a simple test to pull the fuse and test it.

 

[ub7rm]

This seems a great solution. Nothing is full proof, but as said when things don't go to plan with the recode tool chances are the average scrote isnt going to start fault finding. Especially as by then the alarm should be going off and trying to rewire the port, upside down, likely in the dark with no way to open the doors to get at the fusebox is going to put 99.9% off.

Security film on the front windows should slow them down a good bit too.

 

[Zafi]

Very nice - what MY is your car Zafi?

2013

 

[John@ECM-TECH]

I guess it depends how long they are willing to mess about with trying to get the port to work. Most will probably just want a quick and easy plug in and press the button to code new keys. Not try get power to the ports.

Seriously 5 min job. Good idea but a proper thief wouldn't be deterred imo

 

[xpoweruk]

Seriously 5 min job. Good idea but a proper thief wouldn't be deterred imo

That could be difference between waking up or not though.

 

[feva]

If there's no power to it, you'd either have to open the doors (which should be deadlocked) or get power to it (which may involve getting into the car and setting off alarm)

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[ammo-mcr]

You'd be better popping a blown fuse in there

any particular reason why put a blown fuse there...? sorry im new to all this stuff

 

[feva]

any particular reason why put a blown fuse there...? sorry im new to all this stuff

Imo not really. Take them out mark which ones go where, as I've said you'll have to be able to open the doors to get access to fuses.

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[Chris90]

Also worth tweaking alarm config to go off straight away instead of a delay.

 

[AudiLeon]

They might just decide to damage the car in anger.

 

[Meemo]

no one concerned openly saying they have done this when allot of cars are targeted specifically (Audis especially to order and unique cars here easily recognisable) and they can use your post here to know what to do?

 

[feva]

no one concerned openly saying they have done this when allot of cars are targeted specifically (Audis especially to order and unique cars here easily recognisable) and they can use your post here to know what to do?

Meemo understand its a public forum but the obd port technique relys on it being live. The obd port protector devices move it the port or locks it, removing fuses makes it no longer live. They would then have to find a way to stop the alarm, bypass deadlocks to open the doors, all of which takes time. The current method they seem to be using is very quick and the more time taken to steal the car the more they are likely to move on.

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[Meemo]

Once you smash the window you can press the unlock button under the window though. Just concerned for everyone is all

 

[feva]

Once you smash the window you can press the unlock button under the window though. Just concerned for everyone is all

Oh, even with deadlocks active?

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[Meemo]

No idea on dead locks lol not gonna test the theory though just careful not too share too much on your cars security incase, I am always quite wary