CDC55AMG

So I was abrubdtly woke up at 3am to the sound of my 06'CLS55 to the car alarm going off and parking lights flashing. As I cautiouslly make my way outside I tried to disarm the car alarm work key fob and nothing is happening. I cannot unlock the car or get the alarm to shut off.

I look inside the at the instrument cluster and it had a red message stating visit workshop and the gauge lights are on. I then hear a loud whirring sound almost like the engine is revving up but the tach read zero and no loud rumble from the exhaust.

From what I gather it was the engine cooling fans running like a turbofan! On and off, on and off.

My next move was to disconnect the main battery to get all of this to stop. Somehow the trunk was unlocked and when I open it up I see smoke and the uncanny smell of electrical burning coming from the drivers side trunk filled the area! 😵😱

I disconnect the main battery negative first then positive in case there is a short to ground.

For added measure I disconnected the Aux battery under the hood too. The smoke dissipated and I pulled the cover of the access panel in the driver's trunk area where the navigation unit is and some fuses and all looked ok. Now that it's light now I will investigate further.

Going to have to be towed to the dealer.
Has anyone ever had anything like this happen?

I had not even driven the car since 8:45pm Tuesday.

Is there anyway to get it into Neutral while batteries are disconnected... My guess is no.

Thanks!

mrmotoguzzi00

I have heard of this in the SL's but not in the CLS... there is a module of some sort in that area that is known to burn up in SL's.... disconnecting all the batteries was the best thing you could do, may have had some extra electrical work if ya didn't... see what dealer finds...

CDC55AMG

Thank you, turns out the SAM fuse/relay block had started to melt. The car left for the dealer via tow and they quoted me $580 for SAM replacement parts and labor included. The burn area was next to the two blank cavities that did not have relays.

I thought this white relay was the problem but it was not melted and just discolored due to heat.

CDC55AMG

Picking the CLS 55 up today from Elmbrook Mercedes (Waukesha WI) who in my opinion have done a great job replacing the SAM module.... communication was awesome. Price ended up being $1080 after some connectors needed to be replaced in the SAM module and I authorized a piece of trim to be replaced in the back left taillight area since the tech found a hole in one of the push pins so that was $65. They checked over trying to set if they could get water to infiltrate and could NOT.