1st post, tried to search, but could not find a similar problem shown.

While idling, my check engine light came on, I scrolled through the dash menus to find malfunction one. "No Malfunctions" showed, I turned engine off for a minute, re-cranked, but light was still on. I plan to check for codes tomorrow, but if the computer is not reading a malfunction, will there be a code to reset.

Any Ideas anyone?,
Thanks
Jim

 

When check engine light comes on you need OBD2 scaner to read codes

 

That is what I was going to use, but, if the MB computer is not reporting malfunction to the dash display, will the code still print out?

 

Malfunnction dash display will never show you anything if error happens in ECU (emission control unit).

 

I got the codes, said it was 3, but only showed two numbers, one was PO335 and the other was PO435, said it was a crankshaft position indicator circuit malfuntion, other was a very small emissions leak.

I had replaced the crankshaft position indicator a month ago, but do not know if the codes were cleared. At that time the dash was reporting the correct problem. Any way, I cleared the codes and so far so good. I wonder if the emission leak could have been caused by being behind an old truck blowing smoke in the drive thru lane? How do you find a "very small emissions Leak" ,
if the truck was not the source of the code?