I have a 2001 Mercedes Benz c320. Everything was working fine until one day I turned it off and tried to turn it back on but it wouldn't! It would crank and turn in for about 5 seconds then die immediately. I would try to accelerate while on but I would get nothing. No check engine light on or nothin. Only codes I get are P0120 & P0221 . I heard it was fuel pump so I replaced fuel pump and replaced fuel filter! Still won't turn on! PLEASE help!

 

The crank no start is a safety limp feature where car puts itself into safe mode kinda so u cant start yo hurt anything else. Try searching this forum with those codes and it comes up tps throttlebody position sensor. The search function is great. I have a crank no start going on myself but I had p0128 engine coolant sensor. There are lot of diy threads for cheap fixes too. I fixed my own myself someone listed a step by step for me.

 

Thanks for the help but I hope it helps! I want my car running again! If anybody else has any suggestions I'd be glad to hear them!

 

Relax, lean back and search. I'm too drunk to be any help right now but rest assured its fixable.

 

Lol well, at least you made me laugh! But if you aren't drunk tomorrow, PLEASE HELP ME FIND A SOLUTION! I still have 4K to pay off and it's just siting outside waiting to be fixed!

 

P0120 = Throttle/Pedal Position Sensor/Switch A Circuit Malfunction
P0221 = Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance Problem

Looks like you have a TPS on the way out but won't effect starting.

Sounds like CPS failure to me.

Fuel, spark, spark at the right time, air are required.

Check.

CPS (crankshaft position sensor)
Coil packs & plug wires,
Air filter & that airbox is clipped down tightly over the MAF
Fuel pressure at the front rail should be 3.8 bar or 55 psi while cranking. Check at Schrader valve.
Fuel filter
Start enable fuses 31, 52 & 57. 52 is OK or it would not crank.

Good luck.