A8 Parts Forum  

Go Back   A8 Parts Forum > A8 D3 > D3 - Body and Exterior

D3 - Body and Exterior Bumpers, bonnets, glass, trims - Everything outside

Reply
 
Thread Tools Display Modes
  #11  
Old 20th January 2018, 05:22 PM
IT's Avatar
IT IT is offline
Administrator
 
Join Date: Jan 2009
Location: Harrogate, North Yorkshire
Posts: 6,222
Default

Well, not sure what to suggest.

So you're saying that when you first start the car, the drivers door mirror goes very dark, but the rear view is ok.

But you stop the engine. Disconnect, and reconnect the main battery, restart the engine and the drivers door mirror is then ok ?

But the rear view mirror just never darkens at all ?

There is a light sensor in the rear view mirror that connects directly to the roof module - this tells the roof module how bright the car is behind, and then there is a wire running from that module back into the rear view mirror, and canbus will be used to send the signals to both front door controllers, which in turn will generate the required voltage on the wires to the door mirrors.

Its possible there is a fault / connection issue with the rear view, whilst it still sends perfectly accurate signals to the doors.

The fault on start up is weird. Without looking at the measuring blocks between the roof controller and door controllers, its difficult to see what the controllers are attempting to do.

It could all boil down to a simple short inside the drivers door. If the passenger mirror glass were auto dimming, it would tell us a lot.

I'm so not convinced its anything to do with the battery. Temperature and conductivity, quite possibly.

I started a 4.2 Tdi earlier with most of its glow plugs faulty, and it exhausted pretty much the whole battery before it finally fired after a minute plus.

... and it still didn't have any issues with any controllers, even when the dashboard was visibly dying under the voltage drop.....

If you want the auto dim to work, you just need to find the root cause and fix it. Botching around it will only make things worse in the long run.
__________________
For parts enquiries and Forum User Administration please contact customer services directly, not me - enquiry@a8parts.co.uk, www.a8parts.co.uk, or call 01642 783537

The Daily Town Car - 2023 Tesla Model Y Performance. Black with Black. Giant ipad screen, huge sunroof, 4 wheel drive, Tow bar, lots of ooomph and made in China, so actually built properly unlike the Californian ones.

The Family Wagon - 2018 Tesla Model X. Black, 7 Seats, Towbar, Homelink, Enhanced Auto pilot with Summon and self park, Heated front seats, CCS Charger upgrade, MCU2 Upgrade, Falconwing Doors, Self opening / closing doors, Netflix, Spotify, toys, Air suspension, alcantara roof + lots of other stuff......

The 17 year old Driver Wagon 2015 Skoda Citigo Monte Carlo. Alloys, Power steering, Aircon, Leccy windows, Sat Nav, bluetooth, central locking, cup holders, 59 whole bhp. Million times better than my first car. Well jealous.....

The First 20 Audis:

2001 D2 4.2 QS Silver, 1997 D2 S8 Silver, 1999 D2 4.2 Silver, 2002 D2 S8 Dolphin Grey,
2003 C5 RS6 Blue, 1998 D2 S8 Black, 2000 D2 4.2 QS/S8 Ming Blue, 2003 D3 4.2 Ming Blue,
2005 B7 S4 Blue, 2006 D3 3.0 Tdi Black, 1999 D2 4.2 Silver, 2003 D3 4.2 LPG Crystal Blue,
2000 D2 S8 Silver, 2007 3.0 Tdi Q7 Black, 2009 B8 S4 Black, 1998 D2 S8 Agate Grey,
2006 D3 4.2 Tdi Blue, 2006 D3 S8, 2007 Q7 3.0 Tdi, 2006 C6 S6,

The Second 20 Audis:

2011 A7 Sline, 2001 A2 1.4 Tdi Black, 2002 A2 1.4 Tdi Silver, 2006 A8 4.2 Tdi Blue,
2007 4.2 Tdi Q7, 2006 S4 Cab Silver, 2010 RS6 Saloon Black , 2007 TT Roadster,
2010 A8 D4 4.2 Silver, 2006 C6 A6 2.7 Tdi Quattro, 2000 D2 4.2 QS/S8 Ming Blue (again), 2008 Q7 4.2 Black,
2009 C6 RS6 Saloon Daytona Grey, 2001 Fully Loaded A2 Tdi, 2006 Avant S6 Black, 2007 VW Caravelle Exec Black (almost an Audi)
2009 TT Roadster Daytona, 2015 Q7 4.2 tdi lava grey, 2002 GmbH D2 demonstrator, 2006 D3 A8 LWB 4.2 Tdi Black

Most Recent Audis:

2001 A2 1.4 Tdi Black, 2007 4.2 FSi Q7 ABT Blue, 2016 S5 Coupe Launch model, 2004 S4 B6 Cabriolet, 2016 Q7 Sline White, 2006 Q7 4.2 FSi Black, 2012 Q7 Sline+ 4.2Tdi White, 2008 Blue Audi S8

Everything Else

1989 Subaru Justy, 1986 Vauxhall Cartlton 2.0 GL, 1985 Vauxhall Carlton 2.2 CDi, 1987 Ford Sierra XR4x4, 1983 Vauxhall Senator, 1985 Vauxhall Senator 3.0i, 1997 Polo Saloon, 1997 Peugeot 306 1.9 TDi, Ford Sierra Sapphire 2000E, 1990 Subaru Justy, 2000 Subaru Impreza, 2000 Subaru Impreza RB5, 1993 Range Rover LSE, 2005 VW Bora, 2003 Skoda Superb, 2003 VW Passat V6 4 Motion, 1996 Peugeot 106, 2000 Range Rover 4.0, 2019 Tesla Model 3 Performance
Reply With Quote
  #12  
Old 21st January 2018, 02:04 PM
erubus erubus is offline
Senior Member
 
Join Date: Mar 2017
Location: highland Perthshire
Posts: 152
Default

Quote:
So you're saying that when you first start the car, the drivers door mirror goes very dark, but the rear view is ok.

But you stop the engine. Disconnect, and reconnect the main battery, restart the engine and the drivers door mirror is then ok ?

But the rear view mirror just never darkens at all ?
Not quite. on first start, the driver's mirror goes dark and the rear view stays clear but does not auto darken at all. When battery is disconnected and reconnected, the mirrors work perfectly as they should.

The passenger side mirror doesn't do anything as a PO has replaced it at some point but just got generic plain glass mirror, no auto darken or heating.

It has only ever started to do it since I had all the problems with the hot start issue and it was getting jump started every day for 6 months. The battery seems to be iffy at best anyway although I do need to do a test on it.

A battery was coded to the car when it was new sometime last year, but it has been swapped for a different one and back several times so I'm not sure which one is coded to the car. I'd been told that the coding was only for the battery level indicator on the MMI (on this forum) I take it that this isn't the case.

Quote:
If you want the auto dim to work, you just need to find the root cause and fix it. Botching around it will only make things worse in the long run.
Finding the root cause is unfortunately the sticking point.
__________________
Daily drive: 2008 A8 4.2TDi
2003 A8 4.0TDi. 4 zone climate, double glazing, Bose - dead
Other cars: 1980 Land Rover Series 3, 2.25d, hydraulic winch,Van/station wagon/topless depending on my mood
1990 Land Rover 90 factory county station wagon with all the luxury additions, such as a clock and a tape player.
2007 A4 3.0TDi s-line cabriolet quattro
2000 A8 D2 2.8 quattro, looking for a new home - gone
2003 A6 3.0 quattro, in the way... anyone want any parts? - gone
Reply With Quote
  #13  
Old 21st January 2018, 03:41 PM
erubus erubus is offline
Senior Member
 
Join Date: Mar 2017
Location: highland Perthshire
Posts: 152
Default

I managed to find a measuring block in VCDS roof module for Automatic day/night interior mirror, block 003. Light sensor signal status: invalid Mirror dimming value: 0.5%

Door mirror is not dark, so I presume the system would be working correctly (It's daylight ATM).

Roof module is not registering any fault codes.
__________________
Daily drive: 2008 A8 4.2TDi
2003 A8 4.0TDi. 4 zone climate, double glazing, Bose - dead
Other cars: 1980 Land Rover Series 3, 2.25d, hydraulic winch,Van/station wagon/topless depending on my mood
1990 Land Rover 90 factory county station wagon with all the luxury additions, such as a clock and a tape player.
2007 A4 3.0TDi s-line cabriolet quattro
2000 A8 D2 2.8 quattro, looking for a new home - gone
2003 A6 3.0 quattro, in the way... anyone want any parts? - gone
Reply With Quote
  #14  
Old 21st January 2018, 05:39 PM
erubus erubus is offline
Senior Member
 
Join Date: Mar 2017
Location: highland Perthshire
Posts: 152
Default

I can confirm the mirrors operate as they should with the "invalid" status described above.
__________________
Daily drive: 2008 A8 4.2TDi
2003 A8 4.0TDi. 4 zone climate, double glazing, Bose - dead
Other cars: 1980 Land Rover Series 3, 2.25d, hydraulic winch,Van/station wagon/topless depending on my mood
1990 Land Rover 90 factory county station wagon with all the luxury additions, such as a clock and a tape player.
2007 A4 3.0TDi s-line cabriolet quattro
2000 A8 D2 2.8 quattro, looking for a new home - gone
2003 A6 3.0 quattro, in the way... anyone want any parts? - gone
Reply With Quote
  #15  
Old 30th January 2018, 08:19 PM
erubus erubus is offline
Senior Member
 
Join Date: Mar 2017
Location: highland Perthshire
Posts: 152
Default

update: I swapped the battery for the one out of one of the Land Rovers at the weekend and fingers crossed, touch wood etc etc the mirrors haven't done their thing since.

If it lasts a month or two I shall get a 900-1000CCA AGM battery that I can actually code to the car. The battery from the Landy is only 850 CCA and is a yuasa which I cant code to the car - it is fairly new though and has never been discharged so it's in good nick. It needs to be to turn over a 40 year old Land Rover diesel.

Still not going to number my poultry but looking good so far.
__________________
Daily drive: 2008 A8 4.2TDi
2003 A8 4.0TDi. 4 zone climate, double glazing, Bose - dead
Other cars: 1980 Land Rover Series 3, 2.25d, hydraulic winch,Van/station wagon/topless depending on my mood
1990 Land Rover 90 factory county station wagon with all the luxury additions, such as a clock and a tape player.
2007 A4 3.0TDi s-line cabriolet quattro
2000 A8 D2 2.8 quattro, looking for a new home - gone
2003 A6 3.0 quattro, in the way... anyone want any parts? - gone
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 10:08 AM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.