My sad and wierd rear sun shade story
Thread Starter
Super Member
Joined: May 2011
Posts: 975
Likes: 270
From: Fort Worth TX
2020 S560, 2014 SLK55 (Prev. 2016 S65, 2013 SLK350, 2008 CLS63, 2006 E350, 2006 CLS500, 2005 C230K)
My sad and wierd rear sun shade story
Executive Summary: Diagnose more-> work less
Hello everyone, just thought I'd share my story in the hope it saves someone some time and aggravation.
Once upon a time my CLS63's rear sunshade was stuck in the up position. I figured no big deal I'll just spend 2 hours removing it and refurb/replace it and all will be back to normal.
NOTE MISTAKE: While I like to think I'm better than that, I did not do a proper diagnosis and just started disassembly (Which is a PITA btw).
So I removed the shade and didn't not find anything wrong (disassembled the gear box and motor too). But when I went back to test the motor I was surprised to see it only moved once of every 3 times I pressed the button and only in the upwards direction. So I went for my STAR DAS -> Rear SAM -> Actuate the rear sun screen and.... Up works without issues, Down nothing happens. Also note no sensors exist to feedback shade position.
So now it was time to proceed to the wiring diagram (Which should have been one of the fists steps).
SUMMARY OF HOW ITS WORKS (ELECTRICALY): The motor is driven by 12V high current from the car that passes to a 7.5 A fuse and is controlled by a dual relay to enable forward/reverse. This relay in turn is controlled by two rear sam outputs (1 is fwd, 1 reverse). (Relay, Fuse and SAM in rear left of trunk)
With this good bit of information I proceeded to disassemble the rear left paneling in the trunk. And noticed the relay was not activating "clicking" on down but worked fine on up. At this point I ordered a new relay. ($20!)Installed new relay and behold... down still doesn't work (relay won't click)
So now all that was left was to diagnose the module outputs and output (35 I think?) is damaged. Ordered new rear SAM and.... still waiting for it to arrive
Has anyone else experienced damaged rear SAM outputs?
Hello everyone, just thought I'd share my story in the hope it saves someone some time and aggravation.
Once upon a time my CLS63's rear sunshade was stuck in the up position. I figured no big deal I'll just spend 2 hours removing it and refurb/replace it and all will be back to normal.
NOTE MISTAKE: While I like to think I'm better than that, I did not do a proper diagnosis and just started disassembly (Which is a PITA btw).
So I removed the shade and didn't not find anything wrong (disassembled the gear box and motor too). But when I went back to test the motor I was surprised to see it only moved once of every 3 times I pressed the button and only in the upwards direction. So I went for my STAR DAS -> Rear SAM -> Actuate the rear sun screen and.... Up works without issues, Down nothing happens. Also note no sensors exist to feedback shade position.
So now it was time to proceed to the wiring diagram (Which should have been one of the fists steps).
SUMMARY OF HOW ITS WORKS (ELECTRICALY): The motor is driven by 12V high current from the car that passes to a 7.5 A fuse and is controlled by a dual relay to enable forward/reverse. This relay in turn is controlled by two rear sam outputs (1 is fwd, 1 reverse). (Relay, Fuse and SAM in rear left of trunk)
With this good bit of information I proceeded to disassemble the rear left paneling in the trunk. And noticed the relay was not activating "clicking" on down but worked fine on up. At this point I ordered a new relay. ($20!)Installed new relay and behold... down still doesn't work (relay won't click)
So now all that was left was to diagnose the module outputs and output (35 I think?) is damaged. Ordered new rear SAM and.... still waiting for it to arrive
Has anyone else experienced damaged rear SAM outputs?
Last edited by VII; Nov 20, 2015 at 12:58 PM.
Thread Starter
Super Member
Joined: May 2011
Posts: 975
Likes: 270
From: Fort Worth TX
2020 S560, 2014 SLK55 (Prev. 2016 S65, 2013 SLK350, 2008 CLS63, 2006 E350, 2006 CLS500, 2005 C230K)
Yes new SAM fixed it for me but most dealers these days would be hard pressed to properly diagnose something like this.
