Strange Duty Cycle W126.035
 

I went to replace the front pads on my new 420SEL today and check the OVP. Pads went in fine. I found that the idler arm was bad or loose. The ball joints seem OK even with the split boots. (new boot time).

I checked the OVP and resoldered the circuit board connections because I thought it was bad. Last weekend, I did the old KOEO duty cycle check and it was zero (0). Today I checked further and found that the duty cycle is all over the place when running and zero (0) when key on engine off (KOEO). DVM w/duty cycle between pic 3 and ground of the X11 socket.

I'll search some more. Any thoughts?

OK, more. If I read the manual correctly, the zero is actually 100% which comes to no faults found, but the MIL/CEL is on.