code reverse lights to work with fog switch

ok ok ok. keep the flames to a minimum please. I do realize there is a few ways to do this, unfortunately wiring elegantly requires patience and some guidance, neither of which I have.

I've been trying to sort how to wire the reverse lights on a car that has had the auto to 6spd swap. I cannot find a clear answer nor can I quite locate the junction point to go from the trans switch into the harness. Finding a way to hack into the harness going to the back of the car is sort of my least desirable option. so I was thinking is it possible to program (using Vagcom) the lights to work if I use the euro switch and pull to turn on the fog lights? Can I use that signal to energize the reverse lights too?

It is an '09 Rabbit S. I have the switch already installed and it works great with the city lights on.

thanks

Jason

madchemistnj said:

ok ok ok. keep the flames to a minimum please. I do realize there is a few ways to do this, unfortunately wiring elegantly requires patience and some guidance, neither of which I have.

I've been trying to sort how to wire the reverse lights on a car that has had the auto to 6spd swap. I cannot find a clear answer nor can I quite locate the junction point to go from the trans switch into the harness. Finding a way to hack into the harness going to the back of the car is sort of my least desirable option. so I was thinking is it possible to program (using Vagcom) the lights to work if I use the euro switch and pull to turn on the fog lights? Can I use that signal to energize the reverse lights too?

It is an '09 Rabbit S. I have the switch already installed and it works great with the city lights on.

thanks

Jason

Click to expand...

Simple answer is no, you cannot change a reverse light to a fog light with only VAG-COM changes.
However, you do not need to hack the harness to make this happen,
you just need to move pins to new positions in the connectors at the CEC.

The reason for this is rear fog lights are powered from dedicated rear fog pins
on the CEC and reverse lights are powered from
different dedicated reverse light pins on the CEC.
VAG-COM can not change the dedicated functions of these pins.

So to do what you ask you must do two things.
1. Move the two reverse light pins on the CEC to the rear fog light positions.
2. VAG-COM the fog light pins to active and the reverse light pins to inactive.

Swapping the pins is easy with the correct tool AND
the purple master pin lock in the connector body released. 20 minute job.

Still a bad idea. Pull that stunt while driving within view of a LEO and you will get pulled over and ticketed.

thanks JetTurbo. I'd wire it as it should be but not sure exactly where to tie the reverse switch into on the CEC. I assume 12v switched on one side of trans switch and the other lead to the CEC somewhere. that's where I get lost in the woods.

That's why I figured just find another way to toggle the reverse lights. I have the rear wiper delete and thought of using the wiper stalk as a trigger, just not sure voltagewise if thatll work

madchemistnj said:

thanks JetTurbo. I'd wire it as it should be but not sure exactly where to tie the reverse switch into on the CEC. I assume 12v switched on one side of trans switch and the other lead to the CEC somewhere. that's where I get lost in the woods.

That's why I figured just find another way to toggle the reverse lights. I have the rear wiper delete and thought of using the wiper stalk as a trigger, just not sure voltagewise if thatll work

Click to expand...

Sorry I was a bit slow to pick up on the situation.
So you currently have no reverse lights due to the tranny swap.
The automatic transmission controller told the CEC to turn on reverse lights over the CAN-buss,
and of course the manual has no controller,
so it has to be done differently of course.

Wish my Bentley mk5 repair manual still worked,
but is was supplied on DVD and requires win7, and my win7 machine died.
I am sure you could identify the CEC pin needed for the reverse light trigger
with that manual, and then there is a coding change to make that work too.
Possibly someone else could help with that.

If I recall correctly, the rear wiper has its own controller (at least it shows up in settings). So no, is not going to be as easy as tapping into its power source either, with the interval wiping, washer double wipe, etc, it is more complicated than that.

Treating the reverse lights as dual rear fogs would be the easiest solution,
along with the negative connotations that go with it.