Hi everyone, I have a S4 NA FC --

I wanted to tap into the diagnostics plug, so I followed these tutorials:

http://howto.globalvicinity.com/gv_w...i=39&co=1&vi=1

http://www.teamfc3s.org/info/article...odes/main.html

So I made that little LED tester thing mentiones in the first tutorial, checked it -- the tester works fine.

The thing is... I went to my FC, followed the directions given in the second tutorial I posted... connected the tester, turned the key to "ON" position, and nothing happened.

No LED from the tester turned on, nothing. Just the usual things the car does... you know, idiot lights go on, etc.


Why could this be? Is there any way to check if the Diagnostics Plug is faulty/dead?

Help!

 

Yeah, get a copy of the wiring diagram in the FSM (available for free at one of the links in the 2nd gen FAQ) and check for broken, corroded or disconnected wire.

 

Grab one LED. It will have say a RED wire and a BLACK wire.

Insert the RED wire into the top middle socket of the green check connector. The wire in that green connector SHOULD be a BLACK/WHTE WIRE. That Black/White wire is what powers the LED

Put the other LED wire into the socket that has a yellow/black wire in it. That should be the socket on the far left top if looking into the side of the connector that has no wires.

Remove the positive cable from the battery. Go turn the key to ON. Go back and put the positive cable back on the battery while at the same time looking at that LED. The LED should have come on for a couple of seconds and then gone out.

With that setup, and the key to ON, go remove the elect plug from the pressure sensor. The LED should blink a code. Reinstall the pressure sensor plug and the code stops blinking.

Possible causes of the LEDs not working..........................wrong wires connected to the black/white wire in the green six socket connector. The RED wires should go there. The LED other wire in the other socket. It might not be Black. It might be yellow or such instead. But the RED goes to the black/white wire in the connector.

The LED has a diode that prevents it from working if you have the wires connected wrong. If it still does not work, garb a SINGLE LED light and try swapping the wires around. You cannot hurt anything by doing that. But, in general, the RED wire will be the one going to the source of power, which in this case if the black/white wire in the green, six socket connector. Still not work? Find out if the black/white wire is hot or not. Put the red in it and the other wire on the batt neg terminal or the chassis. Should light up if the black/white is hot.

I just did the above with a single LED light. Works.

 

Thanks a lot for the explanation!

I will check this tomorrow