Hi,

Just finished 10 weeks of a 2 yrs auto tech program. I gave it major tune up (filters, sparks, compression, vacumn, pressure, etc). I just finished cleaning the fuel system and MIL came on. I retrieved the code manually from the X11 by push/hold the black button. I got 4 and 10 blink from the led. I got MB's DTC definition from AllData but it has 2 column. The first column has code 1-50, the second column start with 002-144. Which column should I use?

The problem I'm having is rough idling when the engine is warm, gas consumption and everything else seems/sound normal.

Ignition, ECT and IAT sensor checked out ok so far. Others sensors are in progress. I need some experty advice to pin point the problem. Please help.

Thank you

ps. where is the ECM located?