Weird Seat Behavior after Swapping Control Units
11-23-2015, 05:14 PM
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2003 C32 AMG and VW Touareg V8 TDI
Weird Seat Behavior after Swapping Control Units
My C32 had the usual battery flattening behavior and the Convenience feature didn't work, so I elected to replace both Seat Control Units. Pretty standard stuff and mentioned in these forums over a hundred times. My car is a 2003 and its original Seat Control Unit has been superseded four times. As the Seat Control Units are supposed to be backward compatible, I decided to get second-hand versions of the latest standard; 211 870 47 26 for the left seat (passenger here in Australia with rhd) and 211 870 46 26 for the right seat (driver), thinking that whatever problems they had at MB that led to batteries going flat should be fixed after four attempts. The difference in application is that the drivers seat also has to control the steering wheel motor.
All went well with the install until I connected the seats. The right seat cushion switch on the door operates in REVERSE; push the switch forward and the seat goes back, pull the switch back and the seat goes forward, Also, the seat goes all the way forward, but only two-thirds of the way back. And, the head rest only moves about 5mm (1/4 inch). The other buttons work as normal and the Convenience feature works, but in reverse; as soon as I turn the car off, the seat travels forward until I just have enough room to get out.
The left seat also operates in REVERSE, except it goes all the way back and only two-thirds of the way forward. The head rest works as normal, as do the other buttons.
Logic says the fuses are not an issue, nor are the motors, nor are the connectors (which I cleaned thoroughly anyway) and I have normalized until I am blue in the face. Today I am going to remove the door trim and the seat switch assembly and resolder the switch terminations. If that doesn't fix the problems, I am out of ideas.
Is there an issue with using superseding parts maybe.
If anyone has an idea that I haven't tried yet, please chime in.
All went well with the install until I connected the seats. The right seat cushion switch on the door operates in REVERSE; push the switch forward and the seat goes back, pull the switch back and the seat goes forward, Also, the seat goes all the way forward, but only two-thirds of the way back. And, the head rest only moves about 5mm (1/4 inch). The other buttons work as normal and the Convenience feature works, but in reverse; as soon as I turn the car off, the seat travels forward until I just have enough room to get out.
The left seat also operates in REVERSE, except it goes all the way back and only two-thirds of the way forward. The head rest works as normal, as do the other buttons.
Logic says the fuses are not an issue, nor are the motors, nor are the connectors (which I cleaned thoroughly anyway) and I have normalized until I am blue in the face. Today I am going to remove the door trim and the seat switch assembly and resolder the switch terminations. If that doesn't fix the problems, I am out of ideas.
Is there an issue with using superseding parts maybe.
If anyone has an idea that I haven't tried yet, please chime in.
07-18-2016, 07:04 AM
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Join Date: Nov 2014
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2003 C32 AMG and VW Touareg V8 TDI
Weird Seat Behavior after Swapping Control Units
Well 8 months later folks, I have the definitive answer. The car went in for an 'A' Service today and I asked for the programming of the seat control units to be checked. After programming the units to recognize they are in my car, the problems all went away.
So easy.
So easy.
