Indicator lights flashing

[sburt93]

Hi there new guy here with a 2017 a4 avant had the car nearly 2 years and have finally cracked to finally try and sort this huge issue out so if anyone can help it will be incredible. Basically the car likes to spontaniously set the indicator lights off like the alarm is going off but with no siren upto this week when i replaced the battery since then it has done it more often with the addition of the siren this time!🤦🏽this only happens when it is locked not when its unlocked which i have had to do most nights. This is not ideal i know but what more can i do i have checked the fuses none of them are blown ive torn the boot apart to see if it was a sensor on that but no change. Any ideas before i start looking to take out a mortgage to get audi to fix it (derby audi want 180 quid just to diagnose it!) Thankyou in advance 

[Sid2020]

Rear screen has a sensor wire in it that has been known to cause alarm issues if it has been damaged. Window tinters  with a knife or dog scratching it have all been seen before 

[sburt93]

3 minutes ago, Sid2020 said:

Rear screen has a sensor wire in it that has been known to cause alarm issues if it has been damaged. Window tinters  with a knife or dog scratching it have all been seen before 

To my knowledge before i had it the screen had been replaced evidence is broken glass still in the wheel well how will i know where to look? Thankyou for your reply 

[Sid2020]

From memory it’s the blue wires attached to the screen. You can just bridge the wires together to make a circuit. Some models also have these on the qter glasses 

[sburt93]

16 minutes ago, Sid2020 said:

From memory it’s the blue wires attached to the screen. You can just bridge the wires together to make a circuit. Some models also have these on the qter glasses 

Ahh! I noticed that i have two! One thats plugged in and one thats not but i cant see no cables to plug into 🤔

[Sid2020]

If you’ve had a replacement screen it’s possible that Audi only sell one spec glass  for each tint and that would be the top spec so any extra connectors are just left unplugged as there would be no wiring in the tailgate for it. Upload a picture of what you have if you can. A diagnostics should also show up if it’s a glass sensor

[sburt93]

15 minutes ago, Sid2020 said:

If you’ve had a replacement screen it’s possible that Audi only sell one spec glass  for each tint and that would be the top spec so any extra connectors are just left unplugged as there would be no wiring in the tailgate for it. Upload a picture of what you have if you can. A diagnostics should also show up if it’s a glass sensor

Ive just ran out and dismantled the boot 

[sburt93]

Also these are the only codes im really getting regarding the boot 

[Sid2020]

29 minutes ago, sburt93 said:

Ive just ran out and dismantled the boot 

This is the hole that some modules slide into to secure to the frame and that spare wire would plug into that module. Might be for different markets depending on radio frequencies used 

[sburt93]

Yeah i tried to look in there but nothing in there unfortunately🤔

[Sid2020]

26 minutes ago, sburt93 said:

Also these are the only codes im really getting regarding the boot 

May be wrong with this but if you pull your rear panel trim up and off there is possibly a wire that goes to a micro switch that detects the spring loaded plastics flap position, check this is working correctly and activating the switch as easily broken. I know q5 and q7 use this to switch tailgate lights to bumper lights when open and maybe the b9 uses it for another reason

[sburt93]

4 minutes ago, Sid2020 said:

May be wrong with this but if you pull your rear panel trim up and off there is possibly a wire that goes to a micro switch that detects the spring loaded plastics flap position, check this is working correctly and activating the switch as easily broken. I know q5 and q7 use this to switch tailgate lights to bumper lights when open and maybe the b9 uses it for another reason

Yeah ive had that off no sensors there the only sensors i can actually see what are similar to those on a q5 or q7 are in the actuall latch itself they seem to make proper contact from what i can see through the tiny slot its a proper mind screw

[Sid2020]

The sensor in the lock mechanism should display on the dash if it didn’t work. Also your interior boot lights would remand lit for a few minutes even when car is locked if your boot didn’t detect it was shut. Had that fault myself 

[Sid2020]

I would try disconnecting the blue wire plug and using a small length of wire with the ends stripped off or a unfolded paper clip to make a jumper wire for the plug on the tailgate loom and see how you get on, clear the faults and see if they come back 

[sburt93]

I shal give that a try and get back you on that thankyou

[Sid2020]

Do you have comfort access where you can wave your foot under your rear bumper as the fault codes your getting are not what I would expect to see for a glass sensor 

[Sid2020]

Your first post says you’ve had this problem since you’ve owned the car so maybe you do have it and it’s never worked and that’s the fault, the sensor wires are usualy on the underside of the rear bumper spoiler fixed into location brackets 

[sburt93]

Yeah i have it it stopped working for abit but then i changed the battery and it works now 

[sburt93]

Yeah i do have it, but it stopped working for abit, then i changed the battery and now works again 

[Sid2020]

That explains the 2 fault codes. Do they come back if cleared now it’s working. Trying to think of how that sensor or controller would trigger your alarm or what to try to find out. Unplugging it is one way, is there an option in Mimi to deactivate it. 

[Sid2020]

Try locking your car and waiting a few minutes and without your keys go out and see if you can open your tailgate. Just Incase the module isn’t powering down or your key is in range overnight. Always worth ruling out the simple and random things 

[sburt93]

35 minutes ago, Sid2020 said:

That explains the 2 fault codes. Do they come back if cleared now it’s working. Trying to think of how that sensor or controller would trigger your alarm or what to try to find out. Unplugging it is one way, is there an option in Mimi to deactivate it. 

Yeah they never showed before though before i had a new battery its almost like a new batterys lifted a shroud covering the real issues its so weird also tried your other suggestion too but no cigar 

[Sid2020]

Disconnecting the battery resets the cars computers so it may have been deactivated in the mmi. It may be a case of having to climb under the rear bumper and removing the fixings so you can pull it down and access the sensors and control module for the comfort opening, check for corrosion in the plugs and wiring and any visual damage Incase it’s had a rear end shunt at some point. I see the photo of the fault codes had a live data section, this could prove handy while checking the connections 

[Sid2020]

Are they the only 2 faults on your whole car when you run a full scan