[the jury]

If your power seats crap out on you, the part that fails inside is BTS409L1
SWITCH SMART HIGH SIDE SWITCH.

This is what controls the input on the ecu telling it what to do. The relays are generally never at fault. This switch handles the grunt and grind of everything coming into the unit and therefore can tend to fail after a few years.

You can see the PDF for this part here: http://www.datasheetcatalog.com/datasheets_pdf/B/T/S/4/BTS409L1.shtml

You can see the burnt leg and tracers around the unit. Once you replace this and verify the tracers are back in order, your seat ecu should function well.

 

[Kingsbury]

Need more informations

Would like to know more about the procedure ...

I'm french so the term "verify the tracers are back in order"
What do you mean ?

BTS409L1 can be found on E Bay for about $4-5

 

[summicron]

The conductive tracks on a printed circuit board are commonly called traces. The damaged traces are visible in the last picture.

 

[Kingsbury]

Thank you

 

[television]

That PCB has had water damage hence the blue stains, I have never heard of the tracks being called tracers, but there we are.

 

[keyhole]

Guys (and mods)

I have no idea what this 7-year old thread is about. As far as I can tell. it has no relevance to W208 models. If so, this information is useless here.

The OP does not refer to MB - or any particular module apart from the 'ECU', which has nothing to do with seat motor control on W208. Also there are no relays involved in the W208 seat motor control.

W208 has seat control group switches (S91/1, S91/2) as inputs to the left/right front ESA control modules (N32/1, N32/2). Outputs from those modules are taken directly to the various seat control motors.

N32/1, N32/2 modules are located under the respective seats.

 

[summicron]

Right Keyhole! This is the Power Seat Control Module not the ECU.

Power seat ECU repair info - MBWorld.org Forums

At any rate, if it's not the switch, it's probably the motor.