Rear Right Fog Light Troubleshooting (spoiler, it's not the bulb)

[markytuck]

Hello,

So I am looking for some help on what more I can troubleshoot / if anyone knows what could be wrong. I have had an intermittent rear right fog light warning pop up over the last few months and now is permanently on.

Car is the 8P 2.0 TDI 2006 S-Line (196K)

So far I know
-that the bulb works (tested out the car)
-there is no 12v to the fog light housing when switched on
-I have identified the white and yellow wire for the rear foglight
-there is continuity on this cable from the housing all the way to where it goes into the ECU
-there is continuity on all cables from the light switches to the ECU
-the light switches all light up when I pull it out to the fog light front, and then also fog light rear.
-ECU inside looks fine on top
-the single 449 relay in the photo is very hot if thats anything to do with it.

This is where I have got to. I have no idea if it is the ECU that is at fault but welcome to peoples thoughts as to what to test next? The car has been remapped so not sure about swapping out the ECU and if I would loose that remap.

The red end of the multimeter is where the white and yellow cable goes into the ECU.

Thanks in advance!
Mark

 

[NHN]

Remap is in the engine control unit, not the 279 module shown, so map is fine.

Check for any corrosion on the connectors & inside the housing.

3 or 5dr, if latter swap sides & wires round temporarily to suit.