squerly

There is a button on the backrest of my 2008 SL550 that moves the seat all the way forward or all the way back, depending on which side of the toggle you touch. Tonight I'm cleaning my car and touch the switch and the seat moved forward as expected. When I tapped the switch to move the seat back, nothing.

The same switch on the passengers side is working fine, it's just the drivers side. Checked fuses, don't see any obvious problem there. Took the switch out and looked at it but it looks and feels just fine. Seems strange that the switch would just stop working in this manner so I'm wondering if there is something else I should be looking at.

Anyone have any ideas?

cyglee

Try this...using seat switches on door, slide seat all the way forward, and tilt back all the way forward. Then try the seat button. This does a reset on seat memory, I think.

squerly

Nope, that didn't work, but thanks anyway. :-) Tomorrow I will replace the switch with the one from the passenger side. That should tell me if it's the switch or something else. Was just hoping for an easy way out of this but there probably isn't.

cyglee

Accessory battery in good condition? Try again with car running?

Rudeney

I have found that if I use the seat-mounted button to move the seat forward, but then adjust its position with the door controls, the seat-mounted "return" button does not work. I have to either use the seat memory or door seat controls to move it back into position.

squerly

Yes, one of the first things I tried.

squerly

So how do you reset it to default positions so that it works as expected? What you're saying doesn't seem right. The proper way for the 1-touch button to work is that it takes the seat to it's furthest forward position and then return it to the position it was originally at when you hit the forward button. The scenario you describe means the 1-button forward/return would never work again after you set the memory to something other than default.

cyglee

Before you switch parts, try one more time to reset the seats. I did it awhile ago... maybe I moved the seat fully forward, held the switch a few seconds, then fully back, held a few seconds (using the door controls), and it restored the seat button function. Good luck.

alk247

Mine does it from time to time. All of a sudden one touch switches stop working. Just using memory buttons seem to restore the functionality.

Rudeney

What I am saying is that if I press the one-touch button on the seat to move it forward, then touch no other seat controls, the one touch button will move it back. BUT...if I use the one-touch button to move it forward, then use the seat adjustment controls on the door to move the seat in any direction, the one-touch button to return it back will not work. Instead, I have to use the door buttons to but the seat back, or, I can just press my memory preset to move it back.

ronbj99@yahoo.c

My SL-550 had the exact problem with the passenger seat. I carefully pried the seat switch on the R shoulder of the seat up to expose the wiring. You'll need a thin knife blade and patience. Once it is off, turn it over to see three small torx screws. You'll need a quite small torx wrench to remove them and you will not be able to remove the cable connector without unscrewing the mechanism or at least I couldn't. Remove the three screws and you should then be able to unhook the connector. When that is off, you can remove the back cover and see the PC board. Insert a small jewelers screwdriver in the side slot to loosen the PC board from its mountings. Examine the solder connections on the PC board. They will probably look good but the fix is to re-solder them with a precision iron that will let you add a very small drop of solder to each point so any bad one is repaired. Put it all back together and test it.

Caution: If you are inexperienced working with precision electronics such as PC boards or if you do not have the tools I mentioned, Don't even attempt this fix as you will screw it up. Good luck!

scw

Just wanted to say thank you for this, it worked for me. I held the forward door button for a long time as it took several movements to get fully forward. Ditto for the seat fold forward button. Then tried the buttons on the seat and they seemed to make a noise which they hadn't before BUT didn't move the seat. So I returned the seat to where it was originally using the door buttons and then suddenly the seat back / forward worked.
Thanks

Frederick NL

As a side note: having the door open or closed (or opening/closing for that matter) does have an effect on the switch function.
edit: the manual states that the seat controls in the door can (must) be used for an emergency stop when someone or something gets caught/crushed by an auto-moving seat.

TR14ngle

Had the very same issue with my 2006 SL350. Thanks for the tip, worked a treat