i2fas4u

I have a new to me 2011 Q7 TDI Prestige. I recently discovered the left rear fog lamp was not working via the message I got on the dash display. No problem I thought. Removed the bulb but it looked fine. So I swapped the good bulb from the right side with the one I removed from the left. The "bad" one worked fine in the right side and but the left side still doesn't work. I unhooked the connection and it looks OK. Since I know I have good bulbs, what's my next step in diagnosing this problem? I'm ok with voltage measuring meters but its not something I feel I'm really good at. I will seldom use this rear fog light but I always want my cars 100%.

smith2010Q7

check the rest of the bulbs sometimes the wireharness does share between different bulbs, turn might be out, or brake etc, etc.
which you can have another one out which is causing that one bulb to be out also. but your dash board computer will not pick it up causing your fog bulb to be out.

i2fas4u

I've learned a lot in the last few days. What is really happening is that the brake and turn signal lamps in the rear bumper are not working. Both sides. Until yesterday I really never knew how all 5 lamps on each side functioned. I've checked all the bulbs and connections and all looks OK. Is this something that could be turned off? Nothing in the MMI gives me an option.

Its embarrassing to admit this, but I didn't realize the turn and brake lights in the rear bumper were only intended to function when the tailgate is open. It makes perfect sense now. If you were transporting something with the tailgate open the brake and turn lights would not be visible, thus the rear bumper lights are activated. Still doesn't solve my rear fog light issue but hopefully this might enlighten a fellow Q7 owner

smith2010Q7

Attach some troubleshooting if you have not found the problem. Your right and left is on the same wire harness. We have a 14 pin connector under are right bumper. ground 51 is in the right luggage compartment. the light bulb is a diode light sensitive. OHMS check is 1.0 Bar. Aslo a 6 pin connector from frame to the light .
If everything checks out find recommand to get brand new OEM bulbs and replace both left and right do to the sensitive of the bulb.



Q7 rear tail light.pdf