Instrument Cluster Illumination - backlighting occasionally slow to light up

[stevieB]

someone mentioned on here that the lighting on the speedo/revs came on after a delay instead of slowly getting brighter. but i can't find the post.

Anyway mines now doing this, the needles light up red then maybe 15 seconds later the background lights come on.

any suggestions please

[PanEuropean]

My wife mentioned that our car did this for a brief period of time whilst I was away this summer... but, it hasn't done it since I have been back. The subject has been mentioned once or twice before here on the forum.

When you take your Phaeton in for service, there are two 'Service Bulletins' (VW Campaigns) that your VW dealer needs to look at. These are Campaign 97J9, dated 03 February 2005, and Campaign 66C4, dated 02 June 2006. These are not recalls, they are what you could, I guess, call "Quality Assurance Update" programs for Phaetons. The second of the two documents, 66C4, makes a reference in Criteria 6 to checking the software version of the instrument cluster and updating it if necessary.

Perhaps wait until the car goes in for service and has this update done, and see if that eliminates the problem.

Neither one of these two campaigns are applicable to NAR (North American Region) Phaetons. In NAR, VW of America sends out Technical Bulletins on a case by case basis, and those TBs have already been discussed here on the forum at this thread: Phaeton Technical Bulletin (TB) Summary. None of these NAR TBs are 'recalls' - they are just guidance documents that elaborate on how to identify and resolve certain problems that may come up.

With respect to the two European Campaigns mentioned above (97J9 and 66C4), my understanding is that the VW dealers will automatically carry out any appropriate actions whenever the Phaeton next comes in for service. Not all the actions in each document are applicable to every car - it depends on both the VIN of the car (build date) and the equipment fitted to each car. It is also worth noting that the first of the two documents, 97J9, is only applicable to cars with a VIN of WVW ZZZ 3D Z 4 8 008 344 or lower - in other words, 2003 or early production 2004 Phaetons that were built prior to mid-September 2003.

Michael

[Itzmann]

Mine just did this, for the first time I think, a couple of days ago. Quite shocking to be driving with just a bunch of orange needles on black banground.

It did look pretty in an abstract kind of way, though.

[PanEuropean]

Perhaps it's a hidden feature that kicks in after a year or 18 months, just to prevent us from getting bored?

Michael

[stevieB]

Mines Ok again at the monent

[henna gaijin]

Could this behavior be related to ambient light conditions?

Just a thought.

[culverwood]

Mine has also done this a few times but always returned to normal afterwards.

No definitely not ambient light conditions as one occasion was when entering a tunnel and all you saw was the needles, very pretty I agree.

[PanEuropean]

Quote, originally posted by henna gaijin »

Could this behavior be related to ambient light conditions?

An interesting thought, but as William pointed out, it is not related to ambient light. It is a very minor, transient problem that a few people have experienced, but the problem doesn't stick around long enough for any of us to troubleshoot it.

I think that probably the best course of action to take is to ensure that the software in the instrument cluster is fully up to date (ends with either 21 or 22), and then we need to wait and see if anyone with the fully up to date software experiences the problem or not.

Because of the very minor nature of the problem (it only lasts for 10 or 15 seconds on the rare occasions when it does take place), no-one has really gone digging so far to find out what the cause is.

Michael

[Mirage11]

Mine had this problem.

It's okay now but it still happens once in a while.

I suggest doing a software upgrade, perhaps?

[dzier]

This happens once in a while, like several other small electrical glitches. I think when you own the car you get used to these things.

[PanEuropean]

Quote, originally posted by Mirage11 »

Mine had this problem. It's okay now but it still happens once in a while...

Hi James:

Nice to hear from you again! Interestingly enough, my car did the 'no lighting behind the dials' trick for about 15 seconds this evening. I think I will contact Diane at Phaeton Customer Care and ask her if she is aware of a fix for this. I hope it is something easy to implement (like you suggested, maybe software) and does not require replacement of the cluster.

My instrument cluster (controller 17) software is generation 3, revision 21 (this shows up as 321 in the diagnostic scan). There is a complete explanation about how to interpret generation numbers vs. revision numbers at this post: TB: Distortion in the Display Unit in the Instrument Cluster (MFI, or Y24). In brief, the generation number is hardware related and never changes, the revision number is software related and increments upward when the software in the controller is flash-updated.

I think software 21 is the most recent release, I will ask Diane to confirm this when I speak with her next.

Michael

[GA Phaeton]

My dashboard lights seem to have a mind all their own. At dusk when they automatically switch from just the DRL to the full lights, the dashboard and related lights don't illuminate. At least not all the time. ( I know about the switch on the side of the steering wheel and that is not the issue) However, if I manually move the headlight switch all the way to the right the dashboard lights illuminate. Sometime if I cycle the car on and off it will return to the normal automatic operation, other times not.

Any suggestions? A good guess perhaps?

Regards,
HB

[PanEuropean]

Hi Harry:

I am going to take a guess that the problem is one of communication between the various controllers on the car (the roof controller, which manages the light sensor, the central electrical controller, which manages the exterior lights, and the instrument cluster controller, which manages the instrument cluster lights.

So, my suggestion to you is that you have a look at this post TB: Distortion in the Display Unit in the Instrument Cluster (MFI, or Y24), then go to your VW dealer and ask them to check the version number of the software in your instrument cluster (controller 17). If the version number is lower than 21 (meaning, it ends in two digits less than 21, the digit in the 'hundreds' position is not significant), perhaps suggest that the dealership carry out TB 90-05-04 on your car. This will flash-update the instrument cluster software to version 21.

The software updates (there are actually several that will be applied, first it is taken to version 18, then next taken up to version 21) address a number of issues, one of which is occasional disruption in communications between controllers. See if that fixes your problem.

Although this is just an 'educated guess' on my part, it is a reasonably inexpensive action to update this software, and if it solves your problem (which I think it will), it will save all sorts of head-scratching, troubleshooting, taking stuff apart, things like that.

Michael

[boreal]

My dash lights started to flicker last night. The voltmeter in the dash is showing 14 volts.
Alternator? No warning lights are on. Any thoughts?

[DmcL]

noticed this the last few times i have started the car and switced the lights on at night. the cluster back lighting will flicker between full brightness and a bit more dim. does this if i dim the lighting also but not as noticeable.

is this a fairly common thing by any chance or has anyone come across this before and know of a fix? also could it be battery voltage related? been keeping an eye on voltage but its not too low, sitting around 13v give or take a little.

also while im on the subject of battery voltage.. can i charge the battery while its still in the car or would that be a no no? would like to make sure its fully charged then see if the flickering issue changes at all and i dont particularly want to remove the battery as im sure it will cause alot of things to reset and whatnot.

thanks

[PanEuropean]

The backlighting within the instrument cluster does not last forever, and there have been reports of this lighting system failing on other 2004 vehicles. I had the instrument cluster in my car replaced in 2009 to fix this exact problem.

To the best of my knowledge, it is not possible to fix the components within the instrument cluster. The only solution is to replace the instrument cluster.

Michael

[Paximus]

Hi Dan,

Welcome to the forum!

Another aspect from Michael's comment is this: if the 13V you mentioned is the reading on the in-dash voltmeter, it is unusually low. Folks are of the opinion that the software sets the gauge at a nominal 14V unless there is something out of the ordinary going on.

Such a low voltage could also make the circuit controlling the lighting brightness to flicker.

In most other cars, flickering lights mean the alternator is end-of-life. In the P it might not be as simple as that. Do you have access to a VCDS scan?

Cheers,
Chris

[PanEuropean]

Dan:

I have merged your post onto an earlier discussion of the same subject. We do that here in the forum to keep all the information about any given topic together in one place.

In addition to reading what has been said above in this discussion, also take a look at this discussion from 2007: Flickering dash lights problem.

Michael

[DmcL]

Hi Dan,

Welcome to the forum!

Another aspect from Michael's comment is this: if the 13V you mentioned is the reading on the in-dash voltmeter, it is unusually low. Folks are of the opinion that the software sets the gauge at a nominal 14V unless there is something out of the ordinary going on.

Such a low voltage could also make the circuit controlling the lighting brightness to flicker.

In most other cars, flickering lights mean the alternator is end-of-life. In the P it might not be as simple as that. Do you have access to a VCDS scan?

Cheers,
Chris

hi, thanks

i really like the phaeton, mind you its no E30 but it will keep me amused when i take the E30 off the road to toss in a GT3582 and boost it to within an inch of its life

when i first got the car it was showing around the 14v mark, i know on my E30 after replacing the voltage regulator on the alternator i usually see 13-13.9 ish volts depending on whats accessories are on, lights, etc, etc. if the voltage on the dash gauge is questionable i can always stick a voltmeter on the battery with the car running and compare with the gauge in the dash. dont suppose the 3.2 phaetons alternator has a replaceable regulator?

the flickering doesnt seem to happen all the time though and the voltage seems to be in the same ballpark most of the time, sometimes dipping down closer to 12v before coming back up.

not sure what you mean by VCDS scan? i have a code reader that i can plug in to my laptop which has a few nifty features such as displaying airflow readings and whatnot from various sensors/systems. OBD/OBD2 is not really my forte as of yet, im used to old skool stuff with minimal diagnostics junk. more used to manually finding problems by cleaning, poking around or changing things lol

worst case and the cluster needs to be changed is it a simple straight swap with any other phaeton cluster or do i need to match part numbers or anything? will mileage on the new cluster match mileage on the car?

also can i charge either battery without disconnecting them from the car? ie - plug in my charger and just connect it up with terminals and all still on the batteries in the car?

[Paximus]

Hi Dan,

You said you have a 3.2 V6 with 2 batteries (not 1), in which case the car's power supply will be arranged the same as the Phaeton W12,V10 & 3.0TDI and the Bentley Continental and Flying Spur.

The information about how it works is in the VAG doc SSP_272 which is available here. Page 16 onwards describes the dual battery and the power management controller.

So there's a bit more to the diagnosis of some problems than used to be the case. Of course, your suspicion about the alternator voltage regulator is still good, the rest of the complexity is added as an overlay on top.

• In general, the in-dash computer always makes the voltmeter dial read exactly 14V when it's happy, ie the volts are above 13.6. It does read the actual voltage but only shows it on a diagnostics scan. As you say you can measure it at the battery. But the voltage doesn't indicate much about the battery condition.


• As the LH battery ages above 5 years the internal resistance goes up, so the large current draw when the dozens of controllers power up all at once can cause the voltage to drop for a few tens of milliseconds, enough to affect the stored software operation. This causes some odd glitches that are fixed with a new LH battery.


• The best place to charge the batteries are at the battery terminals. Use a charger specified for AGM (glass mat) batteries, in which case it's OK to leave them connected, in fact it's better. If it's some random garage charger there's a risk of blowing one or more controllers, which would probably write off the car.


• It's possible that a defective RH battery can draw too much charging current and drop the volts. But the RH battery is charged from an on-board battery charger powered from the LH battery, and the controller disconnects this charger if it goes on charging for too long.


• The alternator is water-cooled and does have a separate regulator, but because of the labour costs in pulling it most people would probably replace the whole unit.

So although none of that seems to directly relate to flickering dash light, it's just possible there's a link. In any case, having that gauge read less than 14V is unusual and might give weird problems with the car later.

VCDS is the scanner from Ross-Tech that does the job of the €4000 unit used by dealers. It runs software on a laptop. An ordinary OBD-II diagnostics gadget only reads out the emissions stuff. VCDS reads all the car computers including that battery charger, and you can't really diagnose the car without it.

Cheers,
Chris

[DmcL]

honestly dont know if the car has a secondary battery, just read alot of mention on here about 2 batteries and assumed they all had 2.

had a quick google searcg of VCDS and read up on it, same thing as vag-com so yea, know what that is. will have to buy it one of these days.

the battery charger i have is a halfords charger with fast and trickle charge rates, so i can just connect it up with battery/ies in car and charge without worrying about any electronic gizmos getting damaged? wouldnt worry me on the E30 but the phaeton has so much electronic stuff i figured id be better to ask first.

[Paximus]

Sorry I gave a rambling comment to a simple question.

I use a Halfords charger, but it has a GEL switch.

If you have 2 batteries, one is behind the LH panel with the chromed clips on the left, obvious, and the other is behind the RH panel with the netting storage, you have to pull the panel off.

The VCDS scanner can be fun, although it's easy to get obsessive about some minor 'fault' that isn't really a problem. If you check the forum you'll find posts explaining what the free version does v the paid-for one.

Chris

[DmcL]

yea i can imagine VCDS/Vag-Com can be addictive.. i remap and chip older motronic ECU's, mainly E30 but anso some older porsche and whatever else falls into that category that my tuning gear will work on.

there is no gel button on my charger, dont see why it wouldnt work though?

on the cluster replacement.. will any cluster work or does it need to be a specific model or part number and will it automatically display the appropriate mileage?

[PanEuropean]

...there is no gel button on my charger, don't see why it wouldn't work though?

See this post for more information: NAPA Battery Maintainer for a Phaeton (Includes TB 00-03-11, 27–04–01, and 27–06–06). The VW Technical Bulletins (TBs) attached provide more detail about the need for an AGM-specific charger.

Michael

[DmcL]

we dont have napa here in the UK/EU. ill read the manual for my halfords charger but there is no gel switch.. its fairly new tho so may cover gel batteries.

whats so special about gel specific chargers out of curiosity?

also slightly off topic, where can i find any (or all, ideally) wiring diagrams and datasheets/info on the various control modules/computers for the phaeton? also can i check what is and isnt on mine via a chassis number search of some sort?

[Paximus]

Hi Dan,

Sounds like you have a lot of fun with the remap toolsets!

A replacement in-dash display should be the correct one or you may have CAN-bus compatibility problems, it contains the gateway between the two bus systems. Check allegro.pl for non-guaranteed used ones unless you are happy to pay quite a lot for one at list.

There's bucketloads of answers and technical information in this forum, including a dozen replies to questions about the manuals, data sheets and build specs. It saves lots of duplicate replies to use the TOC thread, which the moderators manage, and to use the search feature on the first page, the one just under the blue box labelled +Post New Thread. If that doesn't work, use Google and search for "your topic Phaeton site:vwvortex.com" (no quotes).

The manuals and the build specs for your exact car VIN are available on-line for an hourly fee or search as above for other sources, (see your build codes pasted in the front of the user book, or a full copy on a sticker in the boot; you can do a VCDS scan to list the controller part numbers and the software versions loaded).

Have fun!

Chris

[DmcL]

so looks like ill be needing to get VCDS then lol

yea, loads of fun mapping the E30's have done some things no one has in the 20 odd years these cars/ECU's have been out there.

is there anywhere info/datasheets/wiring diagrams are all in one place or will i just have to trawl the web/forums?

[PanEuropean]

...we dont have napa here in the UK/EU...

The charger is actually made by a company called 'Midtronics', and is sold under various brands, including NAPA.

I think you should be able to find a similar charger without a lot of difficulty. The key points are that you need a robust charger (it is a large battery), and you need one that has a setting to deal with AGM (absorbed glass mat) batteries.

In North America, the NAPA (Midtronics) charger illustrated at the post I referenced above costs about $50, which means that a similar product will likely cost around ₤50 or €50 in your area.

Michael

[Paximus]

is there anywhere info/datasheets/wiring diagrams are all in one place or will i just have to trawl the web/forums?

First stop are the VW SSP pdfs, which run through each of the VAG car companies' core technologies as they were/are developed and have a lot of Phaeton-explicit descriptions. Someone thoughtfully posted many of them free here (check the 201 to 300 index page - start at doc 270), or you can pay £6 an hour and download them yourself (together with your build codes, wiring diagrams etc) from volkswagen here.

Chris