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Discussion Starter #1
My SLK started to behave yesterday like it was posessed. Symptoms:
- Initially key opened just drivers door, not starting
- Battery suddenly dead (Car was standing for 1 day without use)
- When I tried to charge it, it just consumed all Amps and battery would not charge (something leaking to ground?)

I took battery out of car and charged it overnight. That way I managed to charge battery. Today I connected it to car to notice that none of the doors are unlocking via remote. Unfortunately I could start car. Then noticed that fuel door is locked and trunk as well. I could not even open trunk with key.

At this point realised that it must be dreaded PSE....But how to check that as I can't open my trunk? I tried then to lower roof and left roof in middle of operation so trunk was open. Opened lid on trunk to operate trunk lock manually. Then opened trunk, but closed lock so I can continue to open roof and close it then.

Now it was easy as I had direct access to PSE. As you may guess already, there was water. Quite a lot of water, about 2 dl of brownish water:frown:

Opened PSE looked like this:


Somebody had opened it before as foam box was torn out:


Cleaned whole circuit board with contact cleaner and compressed air, looks better:



Interesting find was that some cables have been cut by previous installer. What are these leads and should they be cut or not?


Then installation back to car. I do not like foam box as it does not keep electronics dry. I put whole PSE unit inside plastic bag with ziptie and inside some dry bags (silica) which will absorb any moisture/water:


After that posession was removed and my car unlocks and locks as usual. Also current draw from battery is only 0.01 A after 5 minutes (Car enters sleep):


So my Varta battery which is 74 Ah should last 7400 hours or 308 days from full to empty:surprise:
 

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If you suspect rain, you should never drive a soft top with it down. The car is filled with wires that water might damage. Just lift up the carpet and you'll find plenty. I don't think it's a quality issue; it'd be impractical and expensive to make the wiring harnesses waterproof.

Someone did a butcher job on the wiring. Maybe the unit was replaced? In any case, I'd look into where those wires go or if they are even original? We have a lot of novice Teslas who like to perform electrical experiments. I also think it's a bad idea to enclose that circuit board in a plastic bag. Wiring needs to be exposed to some airflow.
 

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Super Moderator UK SLK 55 AMG 2007
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Wouldn't be keen on using a plastic bag myself.

There was some success by turning the unit upside down.
The circuit board did better that way around.
 

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Discussion Starter #6
I got WIS/ASRA and tried to check wiring diagram for PSE. To my surprise there was no wires with code SW (black) or SW/RT (black/Red). Document number: pe80.20-p-2000-99c and PSE control module is A37 in diagram. Could somebody with more experience check this via WIS/ASRA? I am still wondering where those wires should go:

 

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I don't have high confidence in the following, because I don't truly know. But to me, those red and black wires that were cut don't look original. They aren't inside the bundle of other wires, and it's unusual for Mercedes to use solid colored wires of that size. Plus the solder job at the end of one pair looks dodgy. So if your car runs fine now, I'd tend to ignore them.

By the way, I guess you probably looked closely at the solder joints on the board before putting it all back together? Mercedes has tons of problems in its cars from sloppy original soldering.

Kudos on grasping the problem by the horns and solving it!

Cheers,

Kim G
Redding, CA
Where humidity is not a problem.
 

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Discussion Starter #8
I don't have high confidence in the following, because I don't truly know. But to me, those red and black wires that were cut don't look original. They aren't inside the bundle of other wires, and it's unusual for Mercedes to use solid colored wires of that size. Plus the solder job at the end of one pair looks dodgy. So if your car runs fine now, I'd tend to ignore them.

By the way, I guess you probably looked closely at the solder joints on the board before putting it all back together? Mercedes has tons of problems in its cars from sloppy original soldering.
[/I]
One pair of red and black is soldered directly to board:


I checked solder joints and concluded that I need to reopen PSE during winter and do proper resoldering to all joints:wink:
 

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Registered 2001 SLK230
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One pair of red and black is soldered directly to board:


I checked solder joints and concluded that I need to reopen PSE during winter and do proper resoldering to all joints:wink:
Yes, I was referring specifically to that pair of red and black wires soldered directly to the board. IMHO, if it were OEM, they'd penetrate the board and not be (so sloppily) soldered to the surface.

Cheers,

Kim G
 

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Super Moderator UK SLK 55 AMG 2007
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Hmm, I am no electrician but I wonder if they had an after market alarm,
or one of those kits to start the engine whilst you are still in the house (Finland).

I don't remember anything like that on the pse when I sorted mine (230).
 

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Discussion Starter #11
Hmm, I am no electrician but I wonder if they had an after market alarm,
or one of those kits to start the engine whilst you are still in the house (Finland).

I don't remember anything like that on the pse when I sorted mine (230).
I think you got it right, It must be Alarm, as I found switch from engine hood without wires. So no need to worry about those cut wires.

Thanks!
 
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