Engine Won't Stop...'05 CLS 320 CDI

[Nathaniel6890]

was there a bit about this happening when there's water ingress in the SAM…

cars these days all work in tiny voltage / resistance changes and a bit of damp and the start of some corrosion causes the canbus to have a moment. if not mistaken quiet a few have dried it out and got away with it.. ACF50 is good corrosion resistance stuff that's good on electrics

the issue (engine not turning off) is quite common on Mercedes

It had crossed my mind that it might be water related. The first time it happened, the rain was pretty heavy. When I dropped drove it to work the next day, the problem had temporarily solved itself and it was dry. But I don’t think It’s happened enough times yet to catagorically link it moisture ingress - certainly something I’ll note going forwards.

 

[Botus]

It had crossed my mind that it might be water related. The first time it happened, the rain was pretty heavy. When I dropped drove it to work the next day, the problem had temporarily solved itself and it was dry. But I don’t think It’s happened enough times yet to catagorically link it moisture ingress - certainly something I’ll note going forwards.

I wouldn't wait.... if its a simple as the lids not on correctly / broken and its full of water things might die in a very expensive way

 

[Nathaniel6890]

I wouldn't wait.... if its a simple as the lids not on correctly / broken and its full of water things might die in a very expensive way

Thanks Botus, any ideas on a location?

 

[Botus]

Merc's actual naming is "Dr-side SAM" and in all the cars I've seen (as the name suggests) sits under the bonnet on the drivers side. The odd model actually has the engine ECU hiding on top of it.... its a black plastic box 7" x 9" between the wing and the brake fluid reservoir.

and possibly helping it fill full of water... is the worst possible design of "drain" I've seen on any make of car....(to allow the flood of water and snow coming off the edge of the screen drain off inside the front wheel arch liner) add that with 10 years of leaf litter and its a wonder any of them have working electrics

 

[umblecumbuz]

... cars these days all work in tiny voltage / resistance changes ...

Second that.
And I think that this is something easily overlooked when weird faults arise.
That's one reason why I would never buy a flood damaged car. They might look pristine and an absolute steal, but down the line a few months and all sorts of obscure gremlins raise their ugly heads. And once the gremlins start, they don't stop.

 

[Steve tyers]

Similar to my issue which ended up being the gateway fuse oxidised causing the errors and the engine to run with the key out

 

[Kriss90]

Hi, sorry for bringing up old post. I have just run into exactly same problem (car doesn't shut off , every single error and cannot turn key)as original issue and after heavy downpour. Did changing fuses actually sorted the issue?

 

[brandwooddixon]

Hi, sorry for bringing up old post. I have just run into exactly same problem (car doesn't shut off , every single error and cannot turn key)as original issue and after heavy downpour. Did changing fuses actually sorted the issue?

Original poster hasn't been seen since 2019, so I doubt you get a response.

If your issue only arose after a heavy downpour then I would suspect a SAM unit being flooded with water due to blocked water drains. You'll need to clear the water drain, remove, dry and replace the SAM before anything else, but replacing the fuses may not cure the problem if the SAM is damaged.