Rear brake lights flicker/stay on 5 minutes after engine running

[Thor89]

Hi all, hoping that someone can point me in the right direction. I have a 2007 A6 Allroad 3.0tdi and have an issue with the rear brake lights not operating correctly.

I started to have issues with the ESP light coming on along with my ABS light. Noticed that my rear brake lights were intermittently working. Afeter testing a few things I concluded that I needed to replace the brake light switch. 

I did this and my brake lights worked as usual. Dash lights remained on. After 5 mins of having the engine running/driving, my brake lights come on and either stay on or flicker. Plugged in an OBD11 scanner and checked the faults. I had one for my brake light switch and one for my ABS control module. 

Tried another brake light switch. Had the same results. Checked all fuses, wiring under the dash and everything appeared OK. I decided to send my ABD control module off to ECU testing in Derby and had feedback that the unit was faulty. Had it repaired, plugged back in and bled the brakes, I still have the same issue. Faults won't clear. 

I've checked all usual issues, water in ECU box, replaced the brake light switch again (all genuine), checked harness wiring for corrosion, light units themselves inc connectors, bulbs, changed the clock spring, Sent the unit back to be test under warranty and still have the same issues.

Few points to note:

* my brake lights work fine when my ignition is on

* my brake lights stay on with the brake light switch disconnected 

* my brake lights stay on with the switch fuse disconnected

 

[Steve Q]

You e done a great amount of diagnostic work. You could change the light units or the harness I appreciate the latter you found no corrosion though. Or a diagnostic check. 

[Thor89]

2 minutes ago, Steve Q said:

You e done a great amount of diagnostic work. You could change the light units or the harness I appreciate the latter you found no corrosion though. Or a diagnostic check. 

Yes. My diagnostics are still showing error code on the control module and Brake light switch see below. Brake light switch has been replaced again. ABS control module has come back after being test again under warranty. 

 

OBDeleven data log

Date: 2021-11-16 12:14

VIN: WAUZZZ4F37N101026
Car: Audi A6 Allroad
Year: 2007
Body type: Avant
Mileage: 360710 KM

---------------------------------------------------------------
00 Steering Angle Sensor


Trouble codes:
No trouble codes found

---------------------------------------------------------------
01 Engine

System description: 3.0L V6TDI G000SG
Software number: 4F0910409G
Software version: 0010
Hardware number: 4F0907401C
Coding: 0011312

Trouble codes:
P1653 - Read DTC memory of ABS CM Upper limit exceeded
static


---------------------------------------------------------------
03 Brakes

System description: ESP 8.0 quattro H05
Software number: 4F0910517AB
Software version: 0040
Hardware number: 4F0614517R
Serial number: 00000000000000
Coding: 0016775

Trouble codes:
00526 - Brake light switch Open circuit
static


---------------------------------------------------------------
05 Keyless System

System description: FBSAUDIC6 ELV H31
Software number: 4F0910852
Software version: 0220
Hardware number: 4F0905852B
Hardware version: 242
Serial number: 10601100626575
Coding: 0000145

Subsystems:
System description: FBSAUDIC6 EZS H45
Software number: 4F0910131D
Software version: 0080

System description: FBSAUDIC6 IDG H01
Software number: 4F0910220D
Software version: 0040

Trouble codes:
No trouble codes found

---------------------------------------------------------------
07 Display

System description: Interfacebox H43
Software number: 4F0910732S
Software version: 5150
Hardware number: 4E0035729
Serial number: 350L$067744865
Coding: 0003002

Subsystems:
System description: Bedienteil MMIC6H01
Software number: 4F0910609E
Software version: 0060

Trouble codes:
No trouble codes found

---------------------------------------------------------------
08 Air Conditioning

System description: KLIMABETAETIGUNGH30
Software number: 4F0910043A
Software version: 0020
Hardware number: 4F2820043Q
Serial number: 00000030191009
Coding: 0001302

Trouble codes:
No trouble codes found

---------------------------------------------------------------
09 Central Electrics

System description: ILM Fahrer H17
Software number: 4F0910279K
Software version: 0240
Hardware number: 4F0907279
Serial number: 4F0907279
Coding: 0013121

Subsystems:
System description: Wischer AudiC6 H04
Software number: 4F2910113B
Software version: 0190
Coding: 0064784

System description: REGENLICHTSENSORH13
Software number: 4E0910557A
Software version: 0090
Coding: 0146221

Trouble codes:
No trouble codes found

---------------------------------------------------------------
0E Media Player

System description: MP3-Changer H44
Software number: 4E0910110E
Software version: 0390
Hardware number: 4E0035110A
Hardware version: 000
Serial number: AUZ5ZBF3128780

Trouble codes:
No trouble codes found

---------------------------------------------------------------
15 Airbag

System description: 4E AIRBAG AUDI8RH30
Software number: 4F0910655E
Software version: 0280
Hardware number: 4F0959655B
Serial number: 0037LD0M6PEP
Coding: 0013381

Trouble codes:
No trouble codes found

---------------------------------------------------------------
16 Steering Column

System description: Lenksäulenmodul H08
Software number: 4F0910549
Software version: 0230
Hardware number: 4F0953549A
Serial number: 90054063420165
Coding: 0102042

Subsystems:
System description: Lenkradmodul H07
Software number: XXXXXXXXXXX
Software version: 0090

Trouble codes:
No trouble codes found

---------------------------------------------------------------
17 Dashboard

System description: KOMBIINSTR. M73 H19
Software number: 4F0910930C
Software version: 0120
Hardware number: 4F0920981F
Hardware version: H19
Serial number: 5HS5398D6
Coding: 6253448

Trouble codes:
No trouble codes found

---------------------------------------------------------------
19 Gateway

System description: J533__Gateway H06
Software number: 4L0910468
Software version: 0040
Hardware number: 4L0907468
Serial number: 0900B06C068413
Long coding: F551BE7B703206

Trouble codes:
No trouble codes found

---------------------------------------------------------------
1E Media Player 2

System description: SG ext.Player
Software number: 4E0035785E
Software version: 0840
Hardware number: 4E0035785
Hardware version: H15
Long coding: 010000

Trouble codes:
No trouble codes found

---------------------------------------------------------------
34 Chassis Control

System description: J197 LUFTFEDER H17
Software number: 4F0910553A
Software version: 0060
Hardware number: 4F0907553A
Hardware version: H17
Serial number: 00619002589500
Coding: 0000210

Trouble codes:
No trouble codes found

---------------------------------------------------------------
37 Navigation

System description: MNS ECE H48
Software number: 4E0910887T
Software version: 1030
Hardware number: 4E0919887L
Serial number: 364LO067622211

Trouble codes:
No trouble codes found

---------------------------------------------------------------
42 Driver Door

System description: TSG FA H12
Software number: 4F0910793E
Software version: 0170
Hardware number: 4F0959793E
Coding: 0003642

Trouble codes:
No trouble codes found

---------------------------------------------------------------
46 Comfort System

System description: Komfortgeraet H22
Software number: 4F0910289B
Software version: 0170
Hardware number: 4F0907289B
Serial number: 01027044780000
Coding: 3285755

Subsystems:
System description: LIN BACKUP HORN H03
Software number: 1K0951605C
Software version: 1301

System description: Innenraumueberw.H01
Software number: 4F0910177
Software version: 0020

Trouble codes:

No trouble codes found


---------------------------------------------------------------
47 Sound System

System description: DSP-High C6 H10
Software number: 4F0910223J
Software version: 0240
Hardware number: 4F0035223G
Serial number: 00000000009430
Coding: 0000113

Trouble codes:
No trouble codes found

---------------------------------------------------------------
4F Central Electrics 2

System description: ILM Beifahrer H10
Software number: 4F0910280
Software version: 0080
Hardware number: 4F0907280A
Hardware version: ---
Serial number: 00000000300400
Coding: 0001103

Trouble codes:
No trouble codes found

---------------------------------------------------------------
52 Passenger Door

System description: TSG BF H12
Software number: 4F0910793E
Software version: 0170
Hardware number: 4F0959792E
Coding: 0003642

Trouble codes:
No trouble codes found

trouble codes found --------------------------------------------------------------- 53 Parking Brake System description: EPB CDEC0080 H04 Software number: 4F0910801C Software version: 0080 Hardware number: 4F0907801A Coding: 0000311 Trouble codes: No trouble codes found --------------------------------------------------------------- 55 Headlight Regulation System description: AFS 1 H01 Software number: 4F0910357F Software version: 0020 Hardware number: 4F0907357F Coding: 0000017 Subsystems: System description: AFS-Modul links H02 Software number: 4F0941329B Software version: 0020 System description: AFS-Modul rechtsH02 Software number: 4F0941329B Software version: 0020 Trouble codes: No trouble codes found --------------------------------------------------------------- 56 Radio System description: TUNER EU/US/RDW H42 Software number: 4E0910541Q Software version: 0620 Hardware number: 4F0035541L Serial number: 394L-067718520 Coding: 0000001 Trouble codes: No trouble codes found --------------------------------------------------------------- 61 Battery Regulation System description: J0644 BEM H12 Software number: 4F0910181E Software version: 0590 Hardware number: 4F0915181A Hardware version: 000 Serial number: 00000000167428 Subsystems: System description: von TU3 2612120060 Software number: 4F0915105D Long coding: 344630393135313035442054553332363132313230303630 Trouble codes: No trouble codes found --------------------------------------------------------------- 62 Rear Left Door System description: TSG HL H21 Software number: 4F0910795E Software version: 0050 Hardware number: 4F0959795E Coding: 0003114 Trouble codes: No trouble codes found --------------------------------------------------------------- 6D Deck Lid Control System description: ValeoHeckdeckel H21 Software number: 4F9910591 Software version: 0280 Hardware number: 4F9827851E Hardware version: H21 Serial number: E5030000B Subsystems: System description: ValeoHeckdeckel H21 Software number: 4F9910592 Software version: 0280 Trouble codes: No trouble codes found --------------------------------------------------------------- 72 Rear Right Door System description: TSG HR H21 Software number: 4F0910795E Software version: 0050 Hardware number: 4F0959794E Coding: 0003114 Trouble codes: No trouble codes found --------------------------------------------------------------- 76 Parking Assistance System description: Parkhilfe 4-Kan H09 Software number: 4F0910283F Software version: 0060 Hardware number: 4F0919283F Serial number: 06230634204696 Coding: 0200016 Trouble codes: No trouble codes found --------------------------------------------------------------- 77 Telephone System description: Handyvorb2 H16 Software number: 4E0910336M Software version: 1130 Hardware number: 4E0862335 Serial number: 00000007615203 Coding: 0010920 Trouble codes: No trouble codes found

---------------------------------------------------------------
53 Parking Brake

System description: EPB CDEC0080 H04
Software number: 4F0910801C
Software version: 0080
Hardware number: 4F0907801A
Coding: 0000311

Trouble codes:
No trouble codes found

---------------------------------------------------------------
55 Headlight Regulation

System description: AFS 1 H01
Software number: 4F0910357F
Software version: 0020
Hardware number: 4F0907357F
Coding: 0000017

Subsystems:
System description: AFS-Modul links H02
Software number: 4F0941329B
Software version: 0020

System description: AFS-Modul rechtsH02
Software number: 4F0941329B
Software version: 0020

Trouble codes:
No trouble codes found

---------------------------------------------------------------
56 Radio

System description: TUNER EU/US/RDW H42
Software number: 4E0910541Q
Software version: 0620
Hardware number: 4F0035541L
Serial number: 394L-067718520
Coding: 0000001

Trouble codes:
No trouble codes found

---------------------------------------------------------------
61 Battery Regulation

System description: J0644 BEM H12
Software number: 4F0910181E
Software version: 0590
Hardware number: 4F0915181A
Hardware version: 000
Serial number: 00000000167428

Subsystems:
System description: von TU3 2612120060
Software number: 4F0915105D
Long coding: 344630393135313035442054553332363132313230303630

Trouble codes:
No trouble codes found

---------------------------------------------------------------
62 Rear Left Door

System description: TSG HL H21
Software number: 4F0910795E
Software version: 0050
Hardware number: 4F0959795E
Coding: 0003114

Trouble codes:
No trouble codes found

---------------------------------------------------------------
6D Deck Lid Control

System description: ValeoHeckdeckel H21
Software number: 4F9910591
Software version: 0280
Hardware number: 4F9827851E
Hardware version: H21
Serial number: E5030000B

Subsystems:
System description: ValeoHeckdeckel H21
Software number: 4F9910592
Software version: 0280

Trouble codes:
No trouble codes found

---------------------------------------------------------------
72 Rear Right Door

System description: TSG HR H21
Software number: 4F0910795E
Software version: 0050
Hardware number: 4F0959794E
Coding: 0003114

Trouble codes:
No trouble codes found

---------------------------------------------------------------
76 Parking Assistance

System description: Parkhilfe 4-Kan H09
Software number: 4F0910283F
Software version: 0060
Hardware number: 4F0919283F
Serial number: 06230634204696
Coding: 0200016

Trouble codes:
No trouble codes found

---------------------------------------------------------------
77 Telephone

System description: Handyvorb2 H16
Software number: 4E0910336M
Software version: 1130
Hardware number: 4E0862335
Serial number: 00000007615203
Coding: 0010920

Trouble codes:
No trouble codes found

 

[Steve Q]

Hmm it might need to go to Audi for further diagnosis in my opinion.