Problem with steering wheel adjuster & drivers seat adjustment W209 CLK500

Subscribe
May 21, 2026 | 03:57 AM
  #1  
Hi,
Hoping someone can help me diagnose a problem with my W209 CLK500. Whenever I start the car in the morning, the steering wheel adjustment lever & drivers seat adjustments do not work. However, if I remove fuse 29 (circled in red below), then re-insert it, everything starts working again. What could be causing this? i've tried replacing the fuse itself with a new one, but that is not the issue. thanks.


CLK500 Fuse box
CLK500 Fuse box
Reply 0
May 21, 2026 | 08:18 PM
  #2  
unstable accessories positioning...
Does your CLK have a Diagnostic Link Connector to plugin your MB scanner?

How well charged/drained is your battery ?
Low voltage commonly makes networked modules unstable by engine crank voltage.

A smart battery charger can help along with timely maintenance.
Reply 0
May 21, 2026 | 08:58 PM
  #3  
Thanks for replying. I will look into the Diagnostic Link Connector and will need to get a scanner (I am new to MB cars). But FWIW I just replaced the battery because the one in the car when I bought it was almost dead. The problem is still occurring with the new battery installed.
Reply 0
May 21, 2026 | 09:49 PM
  #4  
battery replacement procedure...
Quote: Thanks for replying. I will look into the Diagnostic Link Connector and will need to get a scanner (I am new to MB cars). But FWIW I just replaced the battery because the one in the car when I bought it was almost dead.
The problem is still occurring with the new battery installed.
What procedure was used to replace your battery ?

was power lost during swap ??
was power kept up with backup source ??
were chassis fault cleared afterwards ??

The long story short is "marginal voltage" may benefit chassis REBOOT** + DTC clear to sanitize unstable networking.


**: Power cycle chassis.
Reply 0
May 21, 2026 | 10:49 PM
  #5  
Power was maintained during swap with a backup source. But no faults were cleared afterwards.
thanks, i will try the chassis reboot and DTC clear as you suggested.
Reply 0
Yesterday | 01:00 AM
  #6  
Quote: Power was maintained during swap with a backup source. But no faults were cleared afterwards.
thanks, i will try the chassis reboot and DTC clear as you suggested.
FYI: some chassis will tend loose window seat and roof settings orhers the radio pin code...

Simply clearing module faults does not help relearn voltage thresholds...only Reboot can.
Reply 0
Today | 04:30 AM
  #7  
just coming back to this.... I gave in and took it to a local mercedes specialist. Two kids and a fulltime job means i dont have time to work on my cars like I used to.

Turns out the Seat module under the drivers seat had faulty capacitors and so was draining the battery and causing the drivers seat adjustment and steering adjustment lever to not work. Apparently you can't get the part from Mercedes anymore so they are sending it away to be rebuilt/repaired and this should sort out all the electrical issues.
thanks .
Reply 0
Today | 07:06 AM
  #8  
rebuilt seat modules
Quote: just coming back to this.... I gave in and took it to a local mercedes specialist. Two kids and a fulltime job means i dont have time to work on my cars like I used to.

Turns out the Seat module under the drivers seat had faulty capacitors and so was draining the battery and causing the drivers seat adjustment and steering adjustment lever to not work.

Apparently you can't get the part from Mercedes anymore so they are sending it away to be rebuilt/repaired and this should sort out all the electrical issues.
thanks .
That sounds like it.
These caps are standard parts.

You should be back on the road shortly.
Reply 0

MB World Stories

The Best of Mercedes & AMG

Explore
story-0

New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

 Verdad Gallardo
story-1

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-2

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-3

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-4

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-5

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-6

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-7

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-8

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-9

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
Subscribe
Currently Active Users (2)
 
story-0

New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-1

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-2

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-3

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-4

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-5

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-6

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-7

Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-8

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-9

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE