'04 W211 - Dash Display Blank

[E55BOF]

The dash display is blank on my 2004 E55; clock, speedo, rev counter, warning lights, all dead; nothing, not even the instrument lights. The central climate control panel display is the same, but it responds to adjustments for more or less heat. The car started normally, and the display was as usual, but when I stopped the engine, the display went white, then dark; it's still dark.

The indicators work, but not the audible warning for them. The COMAND unit works normally, but the steering wheel volume control does not. The electric mirrors, steering wheel adjustment, and windows all function normally.

The car still starts and runs normally. SBC is fine - I can hear it running. I have been getting the 'convenience functions disabled for battery protection' message quite often, but not this morning.

Give me a clue; where do I start looking? Could it be the auxiliary battery (he said hopefully)?

 

[Mrhanky]

My first action, would be to check / the aux battery as it's a fairly common cause of convenience function issues. However, not heard the lights going out before.

Going luck mate.

 

[whitenemesis]

The Aux battery would only come into operation if the main system battery was failing/low on charge.

My guess is a fuse for the cluster? Have you twisted/jiggled the display dimmer knob?

 

[E55BOF]

Already twiddled/jiggled; made no difference.

The auxiliary battery shows a healthy 12.6 volts with the engine off; the main battery, however, was only 11.8 volts. It rises to 14.2 volts with the engine running at idle, so on the face of it (I don't have an ammeter) the alternator is OK. There is a drop of 0.2 volts between the charging points under the bonnet and the terminals of the main battery, so there does not seem to be a problem with the cabling. The battery is a Varta Black, renewed three years ago, but it is a 70AH item, not the 95AH one recommended.

I've put a trickle charger directly on to the main battery, and will see what happens when the charge rate drops to near zero (it's around 5A at present). Fingers crossed...

 

[Deleted member 37751]

Not having much luck with this one so far by the sounds of it?

Any sort of warranty?

 

[E55BOF]

Yes, but an 'obligor' warranty, which is probably underwritten by the dealer. A notional limit of £500, but that's irrelevant; my legal rights have no such limitation. It will need a couple of grand spent on it, but it's an eleven-year-old car with 135K miles on it, and high-end cars have high-end running costs even when they get old...

To be fair, having had Terry give it the once-over at Wayne Gates, most of what needs doing is just maintenance, and doesn't make the car unroadworthy or unfit for sale, and I knew about it and took it anyway. He doesn't think the MoT is hooky.

The only things he found that are clearly the vendor's responsibility to pay for are one engine mounting and a brake fluid change; add to those, of course, (if charging the battery doesn't sort it) the current electrical problem.

The snag in all this is that I bought the car from a dealer in Liverpool, and if he insists I take it up there (212 miles) for the work, it will be a tad inconvenient to say the least. Other than the display problem, there's nothing that makes it undriveable.

I reckon he made at least £3K on the car, and he was very helpful and reasonable (but aren't they all...) when taking my money; let's hope he still is when I'm taking his...

 

[BlackC55]

I expect the main chip on the cluster is dead. Easily replaceable too. We charge £175 for this.

 

[E55BOF]

Thank you for that. Obviously they do go, otherwise you would not know about it offhand. Is there any test I can do to establish if that's the problem, other than a STAR check? How difficult is it to get the cluster out so I can send it to you?

One other thing: the clock has stopped. I assume that, too, is run by the same chip?

 

[E55BOF]

Update now it's getting dark: the exterior lights all function normally, but still no instruments, instrument lights or warning lights. The central climate control display panel is showing figures normally, but dimly. The climate control panel for the rear seats is showing figures as normal; brighter than those in front. The ambient lighting and interior lights function normally. The whole of the speedo digital display - round centre, and small oblong beneath - is in fact permanently illuminated - ignition on or off, engine running or not - with a pale bluish-grey light.

There's obviously some power getting through, so it's plainly not a fuse or duff connection. Knackered chip sounds even more like the correct diagnosis....

Just had a look in the Haynes; very simple to remove the cluster by the look of it. However, does the car have to be on STAR to download data before removing the cluster, or if the main chip is defective, will renewing it mean all the stored data will be lost anyway? Will a STAR session be necessary to set it all up after the cluster is refitted?

I knew I should have stuck with a Morris Minor...

 

[BlackC55]

Check the fuses first.

A Star will just show lack of communication I expect. Nothing specific.

You can send it to me for repair, no probs.

 

[E55BOF]

I have the main fuse box cover off and have read the list, but damned if I can work out which fuses to check. Give me a clue when you get a chance?

I'm glad I haven't sold the '03 yet...

 

[BlackC55]

Look at the fuse box inside at the end of the dash. You have to have the drivers door open to remove the cover.

Off the top of my head I'm not sure where the fuse is. I can check when I'm at work tomo though.

 

[BlackC55]

I've just checked. It looks like it's directly fed from the front right Sam.

 

[E55BOF]

Terry at Wayne Gates reckons these repairs on W211s always fail again. He used to use BBA Reman, but now uses AC tronics. Could I ask, who do you use for your instrument cluster repairs?

 

[AMGeed]

Could I ask, who do you use for your instrument cluster repairs?

Probably Cartronix in Waterlooville who do offer a lifetime warranty on the repair as long as you own the car.

 

[E55BOF]

Do they now? I've been on their website looking at E-class instrument clusters specifically, and it states they offer a two-year warranty.

 

[AMGeed]

Do they now? I've been on their website looking at E-class instrument clusters specifically, and it states they offer a two-year warranty.

You are correct. I looked on their homepage which indicated a lifetime warranty . Then clicking on cluster repair it states 2yrs

 

[E55BOF]

Still much cheaper than a brand new one - somewhere north of £1300...

 

[E55BOF]

It's fixed, I think. Pinch me; I'm dreaming! :bannana:

I'm a spannerman - I can use a multimeter and read a circuit diagram, but that there electrickery is not my forte - so I disconnected both batteries and set about removing the cluster. Then it occurred to me: what do you do when your computer freezes and nothing works? Force a reboot by turning off the power. The cluster chip/ECU is I suppose a (very simple) sort of computer, so - nothing to lose - reconnect batteries, ignition on, and Houston, we have lift off! The display is back to normal. :bannana::bannana:

The clock went to 12 o'clock, then after a few minutes reset to the correct time as the stored data was downloaded from the ignition switch module. I surmise/hope that it was not a hardware problem at all, but a software glitch. I have no idea what caused it in the first place, but rebooting seems to have reset everything and cleared it.

As a bonus, the parking sensors are now functioning normally as well. :bannana::bannana::bannana:

I've driven the car for thirty miles or so, and the problem has not recurred, so here's hoping...

 

[DavidL]

Good news, lets hope it stays that way.