John H

After a short drive, my dash/instrument panel went completely out. Not a single gauge works. All dark.
But the car runs and drives fine and the radio works so, overall, not the worst thing that could have happened.
We have been hit by major rain storms so it's likely a water intrusion issue. Anyone ever have to diagnosis a similar issue on the W212?

CaliBenzDriver

After the recent rain your instrument cluster stays inactive regardless of everything else around it working normally.

As we know... these cars are famous for leaky windshield assembly. The cluster is well built to be reliable.

John, can you scan your car for fault codes?
We are interested to know if the cluster is On or Off-line.

Eventually check fuses for sanity then pull-out cluster to inspect it for signs of water damage.

Do a quick water penatration test to edge your bets on possible cause.

S-Prihadi

See fuse 28 or PDF page 12
Would be similar to your E550 facelift in terms of FRONT SAM fuses assignment to my 2014 E400.
https://mbworld.org/forums/attachmen...12.065-rhd.pdf

Good luck.........

John H

Thanks, CBD. I didn't even think to use a scanner. Using an iCarSoft i have a U015500 code, which is a communication error with the instrument cluster. Follow-up research indicates this is most likely due to water intrusion. Since I have no covered storage and heavy rains are expected for the next week it looks like my diagnosis and resolution are on hold.

John H

Thanks SP. I should have put in my OP that I checked fuses 5 & 28 first - my oversight.

CaliBenzDriver

CBD... LOL 😂

You have found a "no com fault" pointing at your cluster. It has fuse power and car likely soaked by rain leaking inside...

> Now is time to pull back your driver side carpet in search of wetness... it's important to qualify the cause of what's wrong to fix it right the first time.

> Open your Front-SAM top cover: any sign of wetness ?

> If you're not driving this car, disconnect both batteries to prevent aggravating grumblings.
Unprotected MB modules are really sensitive to moisture, none of them are cheap to swap.

Left Coast Geek

phew, once moisture starts getting into the interior of the car, it tends to be fast ride to the bottom. come back on a sunny day after a week of wet, and find the whole inside of the car growing mushrooms and mildew

very small amounts of moisture intrusion was the death of my 1989 VW Jetta at 250000 miles, and our 1987 Volvo 240 at ~ 500,000 miles. Also killed my 1993 Mercedes 300CE Cabriolet around 250k miles.

S-Prihadi

CBD = Central Business District , that is high value property Cali

Since fuse 28 is not blown.........
I am curious on the final result of the findings , if water intrusion on CAN-BUS only , but able to take down power to IC and made it dark powerless.
Is the power cut done by IC for overall safety while protecting its CAN-BUS system and also includes cutting power to itself , like deep sleep mode ?

This will be fun to learn. So far most modules does not have such visual display like IC and if power is somehow loss we only know its loss of function but no other visual indication.

Or, the water intrusion is at IC power/ground wires or interconnect too and brought voltage down so low, IC loss power.

John H

Finally a little dry weather in CA.
I pulled up the carpet and kick panel on the driver's side. It was bone dry. No evidence of any moisture and no damp smell.
I let the car run for 30 minutes with heat on high/floor in an attempt to dry out any cabin moisture. Gauge panel still out.
Open to suggestions on where to look next.

konigstiger

Check f5 (7.5A) @ front SAM in engine compartment if fine, attempt reset by removing for several minutes. If this fails, remove IC to inspect behind including connections.

CaliBenzDriver

So far we know this "No COM" IC is:

1. - Not rain intrusion Footwell carpet
2. - Not wet F-SAM tub enclosure
3. - Not a bad Fuse issue
4. - Not a known common issue

Following IC removal you'll have the opportunity to probe the connections for DC power and CAN signals.

Try to be mindful of what you deal with not to unknowingly transform a sleeping "No_IC" into an intermittent issue, harder to pinch.

I am thinking this is a poor connection, luckily solderless game was kept out of display cluster.

At this point my money is on poor GND return under that driver carpet you've pulled back... MEASURE FIRST so you know what the harness is bringing to IC.

> Definitely disconnect Batts before cleaning with the VIP GND screws at driver's footwell.
🤞

juanmor40

I would look on the ground points on both footwell, here is why




The X30/30 and X30/32 modules are on the driver side, X30/30 takes care of the Instrument Cluster, but also of the right front footwell ground point, and X30/32 also takes care of the Instrument Cluster and the left front footwell ground point

Summary: the instrument cluster communication shares both ground points somehow. NOTE: I am not expert on CAN communication; however, the listed names in the document hints to check both footwell. Open to be corrected if I am mistaken.

===========

When you said the Gauge panel is still out, did you get the instrument cluster out?, i.e. disconnected/unplugged from the electrical connector. How does the connector look? corroded/broken?

MB_FanAddict

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John H

Wow, some really great information. Much appreciated!!

After a day and a half of sunny weather (with the windows partially down) the dash has come back to life! It's great news but it also means the issue has not been resolved and will happen again during the next weeks-long rain storms. However, I am much better prepared with everyone's help!!

juanmor40

Glad to hear the cluster has returned/dried out.

Now the task is to find the water point of entry. The usual culprits:

1 - Windshield: check seal all around. You may want to try putting a thick towel/plastic cover over the dash, and run a water hose over the windshield at a mild flow rate.
2 - Drainage points over the two A-pillars: clean them out using some long plastic like a fish line, and run water down. Check the cabin is not being flooded. It better leak down the wheelhouse to the floor
3 - Underhood: check behind the Front SAM (the fusebox), and be certain water cannot go through the firewall

Need to think about the other entry points from the top-down. There are the floor seal/plugs under the carpet. If someone took them out, water can come from the splash on the road from below and wet some modules.

CaliBenzDriver

The IC was sleeping and after drying a bit it woke up. It sounds like the car has remained powered during drying period. That is not really good news.

My hunch moves from GND posts (dry carpet!) to FRONT-SAM unprotected circuit traces and narrow microcontroller SMD pins. The F-SAM Power Mgt module is highly sensitive to moisture. It gets feed rain directly through it's thick harness bundle coming from the A-Pilar.
There could not be a better setup 🤪 Don't take my word, pull out the footwell plastic cover and inspect.

This whole "sleeping IC" issue still need to be untangled to get a root cause:
- where did rain come in ?
>>> (ROOF seam)
- where did the rain impact IC electricals ?
>>> (F-SAM)


No smoking gun yet:
Collect evidences while things are still wet if at all.
Find the rain entry point and go from there to learn something new with your new friends.
✌️

MB_FanAddict

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