Uh Oh! ML280 slowly dying!!

[ripface]

Hi All,

My pride and joy is starting to get on my wick! 2008 Mercedes ML280 that I've had for two years and with mostly trouble free motoring is slowly dying before my eyes. It started the other day when the rear wiper suddenly stopped halfway across the window. Weird I thought, the screen washer was still working but the wiper was stuck. When I got home I checked again, and low and behold it had reset itself and was working as normal. Hmm!

Yesterday I took the old girl out and noticed that the indicators were not working. Really. Took it back home and started to check functions. The following are now not working:-

Rear Wiper (Screen wash ok however)
Indicators (Including the hazard warning)
Remote central locking (Battery good on the fob)
Fuel gauge reads empty (Tank was filled last time out)
Boot will not open even using the unlock button inside

The car starts and runs ok, but something is definitely amiss. Any clues peeps? Is there a common module that might affect all these functions? The rear SAM was replaced a year ago, and the rear window was popped off and resealed as it was leaking into the rear void and getting water on the SAM. It is dry now, so hoping the rear SAM is not the issue.

Thanks in anticipation,
Ripface

 

[BlackC55]

Sounds like you have a wet rear SAM unit or a SAM unit failing.

Plugging it into a Star will help diagnosis.

 

[ripface]

Hey BlackC55,

You read my mind! Spooky!! I just crawled in the back of the ML and released the boot with the emergency manual release. Popped the right hand side hatch and stuck my hand down in there. Came up wet!! AGAIN!?!?

I had the rear window on that side resealed last year but looks like either it is leaking again, or there is another leak to find. Looks like I'll have some fun playing around with hoses etc to see if I can find the leak.

Any other common places I should be checking other than the rear window?

Cheers,
Ripface

 

[BlackC55]

The rear light seals are common to leak. Not seen a window leak there before.

 

[Jobsworth]

The rear quarter windows do occasionally leak, it comes through the white location pin. More common though is the rear lamp seal as Olly says. The centre brake lamp on the tailgate is another common one. All the faults you list are on the rear SAM. It's possible to get it higher up in the rear corner, and I'd advise doing that with your replacement to avoid the same trouble again. Mercedes relocated the unit to under the rear seat on the 2010 cars, but the loom isn't long enough on yours to get it there.

 

[ripface]

Thanks Guys, appreciate the tips!

I've just pulled the SAM module and took it apart. Some fairly gross white gunk all over the board. I cleaned it up with a soft brass brush, and WD40'd it to disperse any remaining moisture. A few minutes with a hair dryer and it looked as good as new. Popped it back in and reconnected the battery, fired the old girl up and *some* of my functions have come back. Interior light, rear wiper, hazard warning lights all work now. Unfortunately the indicators are still snafu and to make matters worse I've no back lights at all .... bar the left indicator when the hazard warning lights are working.

Guess I'll pull the module again and have another look see. Will definitely look at the tail light seals, was there a recall for the poor seals fitted at assembly?

Cheers,
Ripface.

 

[DSM10000]

Thanks Guys, appreciate the tips!

I've just pulled the SAM module and took it apart. Some fairly gross white gunk all over the board. I cleaned it up with a soft brass brush, and WD40'd it to disperse any remaining moisture. A few minutes with a hair dryer and it looked as good as new. Popped it back in and reconnected the battery, fired the old girl up and *some* of my functions have come back. Interior light, rear wiper, hazard warning lights all work now. Unfortunately the indicators are still snafu and to make matters worse I've no back lights at all .... bar the left indicator when the hazard warning lights are working.

Guess I'll pull the module again and have another look see. Will definitely look at the tail light seals, was there a recall for the poor seals fitted at assembly?

Cheers,
Ripface.

I would get some electrical contact cleaner spray and ensure all the plugs and sockets are clean, WD40 would not be my choice as it does leave a residue that can be sticky

 

[Flyinspanner]

Wonder if there is a bad earth point in the wet location too?
might be worth a look. (Earth for the SAM) contact cleaner as above post.

If the rear lights are the source of the leak, the earth point at lights (if there is one there), the connectors (inc inside female side) on that light unit, and fuses again for all affected circuits.

 

[ripface]

Hi All,

So, I took the hump and put back in my old SAM from last year. I had previously cleaned it up and squirrelled it away for a rainy day (pun intended). It appears this has resolved *all* the issues I was seeing with the soggy SAM. Even the boot opens now, a relief as I was getting a little tired of climbing over the rear seats to work the manual override.

I'll pull the faulty one apart again and pop off the black "towers" to see if I missed any corrosion below them. Hopefully I can resurrect it for another ... yeah ... you guessed it, rainy day. In the meantime it's time to track down the damn leak that precipitated all this grief.

Thanks to all for the help, hints and tips. Gratefully accepted and appreciated.

Regards,
Ripface.

 

[Bobby Dazzler]

Hi All,

So, I took the hump and put back in my old SAM from last year. I had previously cleaned it up and squirrelled it away for a rainy day (pun intended). It appears this has resolved *all* the issues I was seeing with the soggy SAM. Even the boot opens now, a relief as I was getting a little tired of climbing over the rear seats to work the manual override.

I'll pull the faulty one apart again and pop off the black "towers" to see if I missed any corrosion below them. Hopefully I can resurrect it for another ... yeah ... you guessed it, rainy day. In the meantime it's time to track down the damn leak that precipitated all this grief.

Thanks to all for the help, hints and tips. Gratefully accepted and appreciated.

Regards,
Ripface.

Well done for fixing it.

 

[ripface]

Thanks! Happy camper!!

 

[ripface]

Erm, one last question ... is it possible to remove the black towers on the PCB without having to desolder the pins?

?