1999 CLK 430 Driver Seat Stuck in Forward Position
I have a 99 CLK 430 and last week the wife took it so I can do maintenance on her car, and she moves the seat forward. Later that night I move the seat back before getting in and after sitting down I tried to move the seat a bit forward but all it did was click. Forward and back just makes a clicking sound. Up, Down, and backrest adjustments works fine. The next day, I checked the fuses under the hood and in the trunk, and inspected underneath the seat to see if anything had been disconnected, or if there were any obstructions. Fuses were good, wires and plugs seem fine, and no obstructions. Still no forward or back...just clicks (sound like the switch is fine, relay seems to be working). I read other threads that talked about the control module, motor, and track. So I was gonna check that out the next day.
Next day, I take the car out and the seat works fine. Forward and back worked. When I get home, I figure I'll go ahead and clean the track in case that was the problem. I move the seat all the way forward to get better access and clean the track. Then it goes out again. Now the seat is so far forward I can't even get my legs in let alone drive the car. I dont even think my wife who is 5' 2" can safely drive that car with the seat so far forward.
Any ideas. If it is the module, track, or motor, does anyone know about the cost of repair (warranty is up). Also is there a way to manually move the seat back, or disengage the motor. Any assistance is would be greatly appreciated.
You should try lifting on the seat while pressing the button on the seat (obviously not sitting in it). If not, through an independent, between parts and labor I was looking at ~$700.
They took it apart, put it back together again and it works. But I figure it is the worn out track that causes the motor to get stuck. So now I just do all I can to not move the seat. By the way. It has gotten stuck and unstuck on its own a half dozen times in the last few months.
Conclusion: If its stuck in the furthest back position, I'm driving. If its stuck in a forward position, the wife is driving.
(the one furthest forward under the driver seat) while hitting the switch. That should do the trick in getting the motor unseized.Let me know if that works for you.
Trending Topics
The Best of Mercedes & AMG
(the one furthest forward under the driver seat) while hitting the switch. That should do the trick in getting the motor unseized.Let me know if that works for you.
Thanks in advance.
(the one furthest forward under the driver seat) while hitting the switch. That should do the trick in getting the motor unseized.Let me know if that works for you.
By the way make sure the fuse in the trunk (#9?) is not blown. I think the head rest controls don't work as well as the forward/back when that fuse is blown. Good luck.
Just one burnt tracer and leg of this part kept me from leaning my seat forward and backwards. When I switched the plugs on it which changed the outputs and inputs, it then stopped me from moving the entire seat forward and backwards rather than just the upper back, BUT I regained the ability to move my upper seat which was the original burned output and tracer. Some of the plugs are possible to switch if you are in a bind and need a quick fix.
it's under the front of the drivers seat.
Moral of the story: Whichever leg goes bad on that output determines what function you lose on the seat. SOME of the plugs are identical in wire colors and can be swapped to regain functionality of another section of the seat you need more than whatever is currently working.
It's a series of identical inputs and outputs, the only thing that determines what it does is the position of the plug.
Lastly, on some occasions simply unplugging the unit (power plug, larger wires on this plug) for 30 seconds and plugging it back in gives it a reset and provides one pressing of the button to move the seat before it goes back into protect mode on that output.
Last edited by The Jury; Apr 28, 2008 at 01:14 AM.
I pulled my module out as well and noticed the exact same middle leg was missing but when taking a closer look it doesn't seem like it was ever soldered on the board to begin with.
Has anyone tried to replace or reconnect this part?
Please let me know as this seat problem is driving me nuts!


I checked fuses 1st and they are fine. There is a click under seat when button to move back is pushed.
I tried tapping with a hammer. It appears there are 3 motors mounted from front to rear under the seat. Still stuck!!!
How do you remove the seat? I can see 2 star bolts on the rear track but nothing in front to remove. Perhaps its too far forward to see any bolts.
Please tell me what tools I need and where to apply them to get the passenger seat out of my clk320 cab 2001 yr (w208)
Thanks
From there you can acces the motors.
When you here clicks and it doesnt move that means the motors dead or the gears are jammed. more than likely its a dead motor. Tapping on it use to work for me, until the motor just couldn't turn any more. I actually got the problem motor turning with out mounting it, but it just jammed again. I wanted to take it appart and lube it or something but its just not worth it for me. too much work. For those who don't want to buy another motor you can swap the front up and down motor and put it on the forwards and backwards. Make sure you adjust the position of the up and down position before removing that motor. Then you'll have to get used to press up on the control to go forward. I did that just to move the seat foward to the correct position. Should have done that a couple days before so I wouldnt have to put two pillows behind me to reach the pedal!.
I don't think you need to get the passenger seat out if you are just to replace the motor. If you still need to its the four in the corners. The seat has to be moved in the middle to expose the back bolts. Its just four bolts in the corners.
Last edited by johnbun; May 17, 2009 at 08:37 AM.
Here is a few notes:
The motor for forward and back is the middle motor.
To get to the motors :
1) I took off the left side cover with a single Phillips screw going into the back (The head faces the back of the car) and pulling the back end towards the door then forward to unhook it from an slid in tab.
2) The rest of the screws were #HH25 Torx screws.
3) I found it best to remove the 2 screws that hold the seat bottom cushion and it's bracket from the drivers side and a 3rd one AFTER I did the next step because I could not get between the seat and the console to get the inner screws.
4) The whole seat comes off with 4 #10MM bolts inside the track center at all four corners and it makes it easier to get to the bottom motor screws.
5) Once the complete seat is loose (Except for the wiring harness and a vacuum hose) you can get to the front seat cushion screw between the seat and the console. I could not seem to get the back one but with the other 3 off, I could lift the cession enough top get to the top motor screws.
6) Then I could remove the motors.
I did not undo the motor wire harness but I switched the running rear motor with the burnt center motor.
So, for now the button that should raise the rear of the seat instead runs the seat forward and back. Till I get a new motor and switch it out.





