W215 display defective

[RoosterBooster7]

Was driving my w215 cl500 back from the shops yesterday when the display came up "display defective" after which my fuel gauge went to empty, air con stopped, headlights and brake lights still work but distance lights and indicators stopped, seat controls, mirrors controls and central locking stopped working, boot locked itself. I have had an MBA tech visit the car this morning and check it and he thinks it may be shorting somewhere or its the instrument cluster, he cleared the error codes and disconnected the battery but no luck. The car drives and goes into gear but that's about it, heater works on "rest" mode but nothing else. Anyone else experience anything like this? He managed to somehow remove power to the boot through the drivers foot well. Any assistance would be well and truly appreciated

 

[m2287]

Never heard of this one before however there is a big fuse box under the drivers footwell carpet which is probably what he went to.

 

[RoosterBooster7]

See attached DAS readout, also just found out the battery is still the original from 2003, still works no problem but I suspect it could be contributing to the errors

 

[RoosterBooster7]

Never heard of this one before however there is a big fuse box under the drivers footwell carpet which is probably what he went to.

He had a look at that too, checked all the fuses but couldn't find an issue with any of them, including the 2 fuse boxes under the bonnet, I couldn't find anyone with the same problem as mine of the forums, similar but none as catastrophic as this one

 

[m2287]

Does the instrument cluster still work and light up?

 

[m2287]

I’m guessing he checked voltages and that the alternator is charging well?

 

[RoosterBooster7]

He says battery is fine and charging well, 13.44 bolts is the reading on his readout

 

[RoosterBooster7]

Instrument cluster lights up, but fuel gauge drops to empty, outside temperature and time are not displaying

 

[m2287]

He says battery is fine and charging well, 13.44 bolts is the reading on his readout

Shouldn’t it read 14+ volts... sounds like an alternator problem to me (although I could be very wrong!)

IIRC it’s relatively simple to replace them.

 

[RoosterBooster7]

Shouldn’t it read 14+ volts... sounds like an alternator problem to me (although I could be very wrong!)

IIRC it’s relatively simple to replace them.

Could be alternator, I understand these cars have a very low tolerance on voltage issues, I will have to investigate that route, can you think of any temporary fix that might get me to the weekend when I have the time to sort it out? Thanks for all your help m2287

 

[m2287]

Could be alternator, I understand these cars have a very low tolerance on voltage issues, I will have to investigate that route, can you think of any temporary fix that might get me to the weekend when I have the time to sort it out? Thanks for all your help m2287

Other than acquiring a cheap second hand alternator off eBay and swapping them over I’m not sure what to suggest ... maybe replace the battery while you are at it if it’s from 2003.

 

[Flyinspanner]

It may be worth pulling and reinstalling fuses linked to instruments/fuel gauge, as they can get oxidised and build up resistance which can affect voltage.

If there ends up being a fault on the cluster, Cartronix in Surrey(?) can fix them.

 

[Smart320]

I would buy a new battery , not expensive and then see what if anything is needed. No way will a 2003 battery be delivering top performance

 

[RoosterBooster7]

Have found that pulling the fuse for the driver's door let's the electronics such as lights, indicators, wipers and so on work normal again, now I'm not getting "display defective" warning but I'm getting "licence plate l r check lamp" and sure enough they're out. At lease now I can drive the car with lights working again, fuel gauge also started working, time and outdoor temp also displaying again. Now my only issue is no windows work. Passenger side front window can be controlled from passenger controls on door but nothing else, the rear windows are stuck about 1" down and the drivers front window won't work (this is obviously a result of pulling the driver's door fuse) anyone have an idea how I can at least put the rear windows up fully? Then it doesn't look as easy a target I'll have a browse on the forum for rear windows now, it seems like others have also had problems with the rears, thanks guys! Also I will be getting a new battery, usually 5 years is normal for one, I can't believe this one has done 15

 

[m2287]

Have found that pulling the fuse for the driver's door let's the electronics such as lights, indicators, wipers and so on work normal again, now I'm not getting "display defective" warning but I'm getting "licence plate l r check lamp" and sure enough they're out. At lease now I can drive the car with lights working again, fuel gauge also started working, time and outdoor temp also displaying again. Now my only issue is no windows work. Passenger side front window can be controlled from passenger controls on door but nothing else, the rear windows are stuck about 1" down and the drivers front window won't work (this is obviously a result of pulling the driver's door fuse) anyone have an idea how I can at least put the rear windows up fully? Then it doesn't look as easy a target I'll have a browse on the forum for rear windows now, it seems like others have also had problems with the rears, thanks guys! Also I will be getting a new battery, usually 5 years is normal for one, I can't believe this one has done 15

Ok that narrows it down, I bet £20 you have a broken cable in the drivers door hinge causing a short... really common problem and very easy to fix!!!

Rear windows are controlled by an ECU under the rear drivers side seat, have a feel under the front of the seat, there is a small leaver you push up to release the seat base. Once this is up you will have To carefully cut the underlay open which will reveal the ECU which has two connectors going into it. I have found that unplugging them for 5 mins and then plugging them back in resets the system and they will work as normal again (no idea why taking the battery off doesn’t have the same outcome).

 

[RoosterBooster7]

Ok that narrows it down, I bet £20 you have a broken cable in the drivers door hinge causing a short... really common problem and very easy to fix!!!

Rear windows are controlled by an ECU under the rear drivers side seat, have a feel under the front of the seat, there is a small leaver you push up to release the seat base. Once this is up you will have To carefully cut the underlay open which will reveal the ECU which has two connectors going into it. I have found that unplugging them for 5 mins and then plugging them back in resets the system and they will work as normal again (no idea why taking the battery off doesn’t have the same outcome).

I will check this one out tomorrow, just parked the car up, if this works I owe you that £20 and a pint! Greatly appreciate the help

 

[RoosterBooster7]

It may be worth pulling and reinstalling fuses linked to instruments/fuel gauge, as they can get oxidised and build up resistance which can affect voltage.

If there ends up being a fault on the cluster, Cartronix in Surrey(?) can fix them.

If I don't get everything working with the top tip from m2287 I will give them a ring, they aren't far from me, cheers for the recommendation, will keep you guys up to date with the outcome

 

[m2287]

I will check this one out tomorrow, just parked the car up, if this works I owe you that £20 and a pint! Greatly appreciate the help

No worries mate! Just make sure you disconnect the battery first.

Where abouts in London are you, PM me if you want.

 

[mattk1]

Hi 'Rooster' I had a very similar problem with my W215 last year. Slow but total loss of all electric systems, very random and very alarming at times seeing the dash slowly fade to nothing! After all the normal checks and phone calls came to nothing I gave my car to Ollie @ PCS for a few days to see if he could shed any light on the matter.
To cut a long story short it turned out to be a dodgy earth connection. After fitting an additional earth strap and replacing the original the electrics have been trouble free.
Just a thought if you continue to have a few gremlins

KR Matt

 

[RoosterBooster7]

Update: just did a bit of reading as i am starting to suspect the wiring in the drivers door, putting the fuse for the door back in makes the driver's side wing mirror motor start and keeps trying to point the mirror down, checked the wiring harness in the door accordion and sure enough it looks like it's had a "quality" repair at some point (attached photo) , im sure it's shorting here somewhere, when I get back from work today I'll fix up these wires then go down the other routes recommended above. If I've no luck at all I'll give you a shout m2287, see what we can come up with, thanks for all the help guys