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

anziani · #1 01-03-2010, 12:13 PM

I give up. What is he talking about? And what model car?
Anziani
'93 300CE 181K
'95 E420118K

junqueyardjim · #2 01-03-2010, 12:15 PM

I think he is still celebrating New Years Day - and he doesn't want to quit

90MB4matic · #3 01-03-2010, 12:32 PM

Ok let me explain further for u, When testing the Duty cycle of my
90 MB 300E 4matic the inital test (static test) before you start playing with the adjustment is to turn the key on and read the duty cycle. The value according to the manual is 70% or 4 volts, the process is highlighted in the website http://landiss.com/mixture.htm, the info i am referring to is
Static tests
It is suggested that before the active (engine-running) tests are attempted, some static tests should be performed to check a few of the basic components of the Bosch fuel injection controller.
With the ignition on but the engine not running, the duty cycle tells which version of controller is installed. A 70% duty cycle indicates the standard controller with the ability to read some faults by monitoring the duty cycle. 85% indicates the California controller, which ordinarily displays the faults as a blinking LED on connector X92, although it can be programmed to display the faults as an X11-pin3 duty cycle. 100% indicates the controller does not display fault codes in this manner, or is faulty.
Assuming the "standard" 49-state controller (70% duty cycle with ignition on but engine not running, or about 4 volts average), the following tests should be performed before attempting to adjust the idle mixture.
1) Idle Contact: Deflect the air flow sensor plate. The duty cycle should decrease to 10%. If it remains at 70% test the throttle valve switch (Job 07.3-121).

2) Full Load Contact: Open the throttle completely. The duty cycle should decrease to 20%. If it only decreases to 40% test the air flow sensor potentiometer (Job 07.3-121).

So basically what i am asking is that when i turn the ignition ON it does not read 70% it reads 50% WHY IS THAT?

junqueyardjim · #4 01-03-2010, 02:04 PM

I always knew there was a good reason to stay away from those 4matics. Want a good 4WD get a Ford Ranger and don't worry about duty cycle. I thought you were chasing a problem in your wire welder and now you come up with a page that sounds like it is right out of an electronics manual. How sad! Sorry about that, because I know that it doesn't answer your question. But I have been around this Forum long enough to know that the way your first post was written would never get a good answer. You got to write smarter then that to get help - good help

90MB4matic · #5 01-03-2010, 04:57 PM

WOW a smart one, look buddy i asked a question looking for a answer not smart a$$ response "I think he is still celebrating New Years Day - and he doesn't want to quit" It seems like you weren't even trying to responde to the question in the first place so whats the point of responding. If you were TRYING to help you would ask me to explain in furthur detail. If you don't have anything good to say then keep it to yourself its a simple question either answer it or don't respond.

PS Ford Ranger, its almost embarrasing you own or like Mercedes.

junqueyardjim · #6 01-04-2010, 09:52 AM

You are correct! I wasn't answering you question and nobody else did either. There are plenty of people on this forum that understand the 4matics very well, but that didn't get you the answer. You want an answer, write it so we can understand it!