W215 CL500 Good and Bad news Cluster****

[Hawkeyethenoo]

The Machine passed it's MOT today, first time of asking since the last ticket to ride experied, Oct 2022. En route hame from MOT station, the instrument cluster went dim and then, stopped working completely. No gauges nothing, blacked out. That was the highs and the lows of today.

Bugger... Car drives fine, heater, windows all work fine. Headlights now come on with and stay on until the ignition is switched off, related, and the left hand indicators have ceased working, related.

Had a quick look at the 5a fuses for the cluster, there's three of them and they all seem, fine. Now parked up with the battery disconnected. Checked for fault codes, none, it's a wiring or relay issue, or the clocks have just packed in? Anyway, 12months ticket to ride was the mission achieved for today.  Focusing on the postivies.  It's still great to look at.

[SiC]

I seem to remember that the regulator goes on these clusters. Either solder joints or the regulator IC itself, I can't remember exactly. Merc want an arm and a leg for a new cluster but they most certainly can be fixed. 

[Hawkeyethenoo]

11 hours ago, SiC said:

I seem to remember that the regulator goes on these clusters. Either solder joints or the regulator IC itself, I can't remember exactly. Merc want an arm and a leg for a new cluster but they most certainly can be fixed. 

Thanks. The way the backlight went and then the gauges failed thereafter would point to the cluster itself losing power. There's a couple of places I've found which will repair it as a sent in item. It's been perfect up till now so can't grumble too much. From what I can see the cluster can be removed without removing the dash panels which I hope is the case...

Cluster shown working.

Pre_MOT photie. Now wearing Goodyear Eagle F1 tyres as fitted last year before the Euro trip.

[SiC]

I seem to remember that as the failure mode. The main regulator internal and power drive ICs to the cluster fails or even falls off and it all goes dead.
https://www.mercedesmedic.com/instrument-cluster-s-class-w220-cl-class-c215/

[Hawkeyethenoo]

Okay, battery reset and the three 5a fuses replaced and no difference. The fuses are getting power 14v, kinda looks like it's a clusterfuck after all. Bonus MOT ramp photies.

 

 

Could we worse, could be a Disco 5 with a borked engine....

[Hawkeyethenoo]

Well that was easy, stereo removal key either side of the cluster, click, click, pull and removed. Remove single wiring loom plug and the job's jobbed. Next !

 

[SiC]

Anything rattling loose inside it?

[Hawkeyethenoo]

4 minutes ago, SiC said:

Anything rattling loose inside it?

Just gave it a firm shake and nope, doesn't sound like anything is.

Will be calling this company in the morning and seeing if they can diagnose the issue and fix the bastid. Linkage

[Hawkeyethenoo]

Have put the battery on the 6amp charger, will let that boil away overnight and re-test the cluster before committing to posting it out. Back of my mind saying could still be battery issue, but unlikely really.

[Rusty Pelican]

On mine the actual plug was iffy and needed a wiggle to get it working , same symptom , gauge cluster just vanished 

 

[Hawkeyethenoo]

1 minute ago, Rusty Pelican said:

On mine the actual plug was iffy and needed a wiggle to get it working , same symptom , gauge cluster just vanished 

 

Thanks, will try that too.

[chaseracer]

Hope it's the cheap&easy fix... #fingerscrossed 👍

[DeanH]

Job for @cobblers maybe?

[stuboy]

4 hours ago, Hawkeyethenoo said:

Just gave it a firm shake and nope, doesn't sound like anything is.

i know few people need a firm shake..lol

[Hawkeyethenoo]

Battery fully charged, cluster connected and connector wiggled and nothing. The only light which seems to still work is the SRS system. Headlights still coming on with the ignition, turn signals now inoperative.

[Hawkeyethenoo]

Found a repair company much more local, Stirling. Will drop it off with them today so they can check it out and report back... Rather not post out in case it gets damaged or lost in transit.

[SiC]

It really need to go to someone who has experience with these imo. They will then have a proper rig to power it up on the bench and confirm if it's really the cluster. Does sound like it's the cluster though from remote internet diagnosis...

[hairnet]

Cheap sat nav ftw

Till it's fixed obvs

[Hawkeyethenoo]

Works on the test bench.

[DeanH]

Good and bad news I suppose. Don't envy you tracing the wiring.

[Hawkeyethenoo]

Plugged the cluster back into the car and it's still not getting power. Thinking, with this and the headlights and indicators not working this could be a SAM module related issue.

https://www.mercedesmedic.com/mercedes-sam-module/

 

[Hawkeyethenoo]

I'm on the fuse box hunt now, have checked all three fuse boxes found thus far, front left and right and rear under rear seats. There's perhaps another one, according to this thread. But I've had both dash end covers off and it's not hiding in there.  The 3 fuses relating to the cluster are on the passenger fuse box and are okay drawing 12v.

All the fuses checked out, except a couple marked in red. Couldn't get a reading from them. Removed, checked and refitted, same.

Fuse box covers have remained on and closed, no obvious signs of previous water ingress which is good.

 

[Vimesy]

I thought that the W215 used a gateway module, not the later SAM unit?

[Hawkeyethenoo]

14 hours ago, Vimesy said:

I thought that the W215 used a gateway module, not the later SAM unit?

Cheers, could be! I've had a look and it seems there is what looks like SAM modules on both front fuse box sides along with modules for the ABC etc on the N/S. It's going to an MB Indy to have it diagnosed with STAR or whatever, as I'm just chasing my tail and don't want to start fecking with things I know less than nothing about.  

The good news is the modules appear to have good access, so half the car doesn't need disasembling to get at them.  Bonus!

[Hawkeyethenoo]

Didn't stop me from buying more tools lol. £60 via Halfords trade inc postage. Will have a play later.

[Hawkeyethenoo]

Have made some progress via ODB diagnostic. There was a long list of 62 DTCs on 17 systems  to start with,  got those down to those below.  Recurring.

 

Pretty sure now it's the front right SAM module which is on the fritz. Items in yellow are linked and communication errors. Next step will be to remove that module for repair/replacement....

[SiC]

Is the door module shorting out the CAN bus and not allowing the instrument cluster to talk to anything else? Thus it appearing dead. 

[Hawkeyethenoo]

4 hours ago, SiC said:

Is the door module shorting out the CAN bus and not allowing the instrument cluster to talk to anything else? Thus it appearing dead. 

It could well be that, yes, but I'm going with the SAM module first as everything works on the doors even the power close, so I think that's a symptom rather than the fault. That's my hunch at least. Cheers.

[Hawkeyethenoo]

Right front SAM module removed. Couldn't find anything obviously wrong or badly corroded, quite easy to remove. Now refitted loosely for now until the replacement arrives. Same faults remain are current. Have sourced an almost identical replacement, same part number, firmware and software versions, just from a slightly earlier production car. Marked Q4, while the original is Q5. Best match available in the UK. No expense spared etc. 

[Hawkeyethenoo]

New-to-me unit not arrived yet, Yodel missed delivery. Phoned them online chat later, asked rather then wait till Monday for redelivery, I'll collect from them thanks. That was sorted. Arrived at the collection point today, no SAM unit. They checked again. Turned out the driver on missed delivery return dropped it in the wrong bin, which was meant for return to sender and off tae Glasgow, it jolly well went. They, Yodel, hope it'll be returned to Perth tomorrow as it's still addressed to me, ken. I've to phone them at 9am. Not holding my breath... Shit happens. Proves that I need another CL500 as a 'parts car'.