Mercedes C-Class Exterior Pillar Posts Trim Set "engine switches driving" Questions

...key a quick turn the car start and runs great and everything inside functions normally, the check engine light is on throwing the code " serial communication link " sounds like a dodgey ignition ...

...stuff eh, LOL. On the front diff there is a section with a vacuum chamber on it. That is what uses engine vacuum to engage the front axel for 4 wheel drive. Although some are electric. You will know ...

...'s FULL,replace fill plug,check both are tight.replace skid plate.regarding 'stuck' situation;start engine,check for leaks .stop engine un-chock wheels..turn switch to 4wd H.if on pavement drive ...

...of the trans while still plugged in and get someone to cycle the 4x4 switch while the key is on (engine off) parking brake engaged and truck in ...

...driving. Also speed gauge shows that im going 20-30 mph faster than i am. For example at 60 MPH it shows i'm going 90 MPH :) Code p0401 (EGR valve issue aka exhaust gas recirculation valve issue) I ...