Diagnosing Faulty Rear Blinds
 

Hi folks,

Recently bought a D3 A8 that has electric blinds on the back doors but both are entirely unresponsive... Read that pulling and holding the window switch for the door also activates them and again unresponsive so not sure if this implies a motor issue rather than switch?

Any advice on how to diagnose would be appreciated, clearly not a must have item but working my way through a few issues and would like to get everything working.

Cheers,
Chris

Hi Chris,

There are two ways of operating the side blinds - the roof console above the rear seats and the window switches.

If neither are working, it's unlikely to be the switch (especially if the window switches still work to operate the windows).

Do you have access to a scan tool to scan for errors?

Yes tried both and no response at all from either.

Psyche from this forum has kindly offered to run a scan (other issue) so maybe that will shed some light, assuming checking voltage at the motor when activating the switch to check for increase would help diagnose...

Cheers,
Chris

How are they fused?

Hmm....good question..... Does seem like the circuit isn't completing due to the complete lack of any noise....

Any one know if there is a fuse specific to them?

For clarity the rear electric blind and rear electric windows all work fine....

Cheers,
Chris

Check the manual, I don't have a D3 any more but you will find a fuse diagram/table and that would be my first point of call +++

There's a thermo-fuse for each rear door wiring harness. So if the rear windows move down then the fuses are good. Each blind motor is connected to its door control module (there's a control module in each door). The door control module will activate the blind motor if it receives an input command, either from the switch on the door or via CAN from the roof module.

Have you been using the rear door button to move the window up / down? If yes then the button is good, and we already know the fuse is good.

Odd that both sides don't work and the roof button does nothing. It's probably a coding issue with each door module, or very unlucky that both right and left blind motors have failed.

Once Psyche scans your car we'll know more.

So, went out and had a play around to check a few things;

- rear windows work from switches on rear doors
- rear roof panel buttons work for lights and back window blind
- pressing side blinds button on roof panel or holding rear window close on drivers contrails has no visible or audible effect, no clicking, whirring or to my eye dimming of lights....

I got a scan done a few weeks ago (only have paper copy or I'd paste it) and nothing I can see....address 62 and 72 for rear left and right doors both listed as "no fault code found"....

Appreciate all the input so far, got a few different little "foibles" so may be looking for further support in near future!

Cheers,
Chris

Can you post the coding values for the rear doors.

Total newbie on all of this so might be wrong thing but the value against "coding" for both doors is 0032623....

Thanks again for taking the time!

Ok, done the maths on that code. It does seem the value of 128 is missing from the coding total. 128 is the value for Electrical Side Shades installed (PR-3Y8).

When you next have the car connected to VCDS, or another tool, change the coding to 0032715. I'm 99% sure that will sort it.

I might be jumping the gun as it's not fixed it yet....but to even have a clue what your talking about I'm already impressed!!

While I have your attention and you are clearly clued up on these things.... :-) ...... From research I believe the tv tuner would be "address" 57, I was told on my car it had been "coded out" as it was analogue, on the scan I have this address is completely missing, can this simply be "switched" back on? Keen to have the option of using the aux inputs.....

I'll report back on the blinds!

Cheers,
Chris

Coding error seems plausible. 32623 is 0b111111101101111.
All options on is 2**15-1 (0b111111111111111) which is 32767 decimal so this is 144 less = 128 + 16 (the two zeros above), so whatever those options are they are turned off.

The TV is on the optical MOST bus. This is a master / slave network with the MMI control head as the master. The master will assign each node in the network a physical and logical address. If the TV was just coded out in the Gateway installation list the Gateway will log an Incorrectly Coded error as the MMI control head knows of the TV's physical presence and will relay this to the Gateway. So the TV also needs to be removed from the optical loop for no faults to be logged. Just poke your head in the boot and see what's what. Post a photo if need be, we're all friendly here +++

Nice one thanks. I'm pretty sure the unit is physicality there as I still my head in to check previously.

I'll have a better look and take some pictures tomorrow.... Will see if physical wiring looks connected.... From other reading am I right in thinking that if it's "disconnected" it would need to be looped/bypassed as the components are connected in series?

Thanks,
Chris

Yep, that's correct.

So, picture attached. Without removing stuff I can't be sure but from the red plug just sitting there I'm wondering if the tv unit has physically been removed?

It looks like it's still there. From front to back; DAB radio, FM radio, then the support rack with the TV unit at the back with the green and brown aerials connectors. There's also an optical loop connector completing the MOST ring. The red connector is where you will add the AUX inputs.

Ah ok, I'll see if the scan sheds any further light and report back.....on the aux inputs point, I was under the illusion the as l was rca input to the tv tuner that you then had the option of selecting via aux 1 and aux 2 on the mmi?

At the moment, when I select CD/TV it is only CD that actually comes up, no option to change source to tv or aux.

Thanks again,
Chris

The AUX1 and AUX2 inputs are connected to the TV. So once the TV is back in the MOST loop you enable AUX1 and 2 from the setup or green menu (not sure which menu) then they, and TV, will be selectable from that button +++

The inputs you add to the red connector will look like this...
http://forum.a8parts.co.uk/showpost....8&postcount=25

Just re-read and spotted this, so from the picture can you spot a loop connector bypassing the tv unit?

Yep

So....guessing it's been looped out as it's gubbed!

Disconnected the ring, connected up the tuner and fired up the MMi, nothing. Swapped back to ring and all good, then done it again for good measure in case I hadn't clicked in right or something but clearly not.

Do original analogue tuners get sold, as above appreciate the tuner is worthless but looking to utilise the aux inputs.

Thanks
Chris

It may be faulty, one reason why the previous owner looped it out. Did you also connect the red plug to the TV?

Just looked on ebay for the analogue units (4E0919146), quite surprised by the optimistic pricing! Maybe a forum member may have one laying around for cheap if yours is dead.

No I didn't plug in the red plug actually, I'll try that!

Yeah, that plug supplies the power! :D

Haha, what a muppet.... Although still doesn't work!

I'll get the scan done first then stick a wanted ad up perhaps....

Damn! :-(

So...... Psyche kindly scanned the car and changed the coding on the rear blinds, good news is the motors etc all work, bad news is they've been coded out intentionally as there must be a short circuit on the switch as they constantly go up and down, up and down on and on!!

There has/is water ingress so think perhaps the switch on the roof panel would be the culprit, I'll pull it off and have a look once I've got the water issue resolved....

On the tv, I've got one coming this week so will plug it in once received and fingers crossed that'll be that resolved and I can fire in a Bluetooth receiver into one of the aux ports....

The scan didn't show the source of the intermittent mmi cut out but it's also not happened a few days so perhaps water related and dried out for now.....

Glad to hear you're a little closer to a solution. Hopefully, now it'll be a simple case of buying a new switch or two from our sponsors.

Chris,
For some reason I have managed to miss this thread, my apologies.
Matty spotted exactly what I spotted in the first photo, i.e. the Most Loop and the red plug.
I was about to PM you and suggest I sent the money back to you, then I read on and realised it looked like there had been a reason for dissing the TV Tuner. So let us play it by ear. If it works then all will be good.
Are you happy with the Aux 1 and Aux 2 feed connections? I use the Kufatec ones because they are coloured correctly for RCA connections.
You can also use a third set of cables to give you Aux Out for Rear Seat Entertainment (RSE).
Please keep us all informed, we are very interested.
Psyche, good on you for helping.
What a Forum this is.

Ye I'm hoping the old unit was coded out and looped out due to the fault....plugging the new one in will, fingers crossed, see it pop up on the source list!

I've not got any leads yet.... Sure I've got a 3.5 to rca kicking around so will at least be able to test via this.... Will be looking to use the aux predominantly for a Bluetooth receiver for streaming music and podcasts on longer journeys....

Fingers crossed it's not like the blinds and a symptom of a deeper issue :-)

As for the forum, I've had a fair few "marques" over the years including Subaru, Porsche and Lotus..... Being an enthusiast I regularly use the relevant forums but rarely have I seen / experienced the helpfulness of this forum....also refreshing that I've yet to read a thread that has become a battle of childish keyboard warriors!

Sadly new unit has the same issue... arrggghhhh....

In the interests of "tidying" things, new thread on the TV tuner specific issue created here - http://forum.a8parts.co.uk/showthrea...813#post126813 - any and all input appreciated!

Chris