PeachParts Mercedes-Benz Forum - View Single Post - When testing the Duty cycle, why do I get 50% when koeo

JamesDean · #24 11-02-2010, 01:26 PM

I'm attacking this issue across a few cars.

190E 3.0 reports 70% Key On Engine OFF
420SEL reports 30% Key On Engine OFF
560SEL reports 80% Key ON Engine OFF

190E then throws a 50% code once its been start and has been running for a while.
420SEL runs normally, a little rich but operations are normal.
560SEL has a high idle problem, and continues to throw 80% fault.

I was talking with a gentlemen over on BenzWorld and he thinks that if the system throws a fault number with Key On Engine off that the device associated with that fault has given the CIS unit an improbable input or an input that is way beyond out of spec...

Example:
30% on a 126 is a Coolant Temp Sensor Fault. If the system is throwing this when key on engine off, then he and i suspect the CTS has gave the CIS-E a goofy value..CIS-E expected range x to y, and CTS provided something no where near that..

Thats our running theory right now, I'm going to change the CTS on my 420 and see if that clears the problem..

Lots of people having this same "problem".. Hopefully we'll get our heads around it.