Date registered: Dec 2005
Vehicle: W211 E320 Bluetec R129 SL500 - $1300 car ........ Ford F350 6l
Location: CA Bay Area
Mentioned: 9 Post(s)
Quoted: 1058 Post(s)
Hats of for DB.
I took apart the one on W210 and it was potentiometer with some kind of composite resistor. I cleaned it, checked for damages and showing no visible damage the thing would keep on failing every couple hr.
Good thing it didn't fail completely, so resetting ignition was pulling the engine out of safe mode.
Bad news is that if it fails -there is no backup.