Hi, I have C240 2003 model W203 Could someone please let me know where in tank Fuel pump relay is fitted on this model.
My car does not fire up straight away when the ignition is switched on, instead after an average of 6 times cranking it starts up. once switched off for 20 to 30 min it gives the same problem in starting up. I check the voltage on a connector on in-tank fuel pump and found 0v, that is no voltage at all to in tank fuel pump, which means this fuel pump is not operating due to no voltage and that is what causing a start up problems.
would you please help me in the following,
A) Where in tank fuel pump relay is fitted ?
B) where In tank fuel pump circuit/wiring diagram can be found or any of you if have please pass it on to me.

Thanks and hope I get some +ve replies.

 

I presume you checked for voltage while cranking? Relay is in rear sam. One Tip. A better way to test is to use a fuel pressure gauge and also check if it has holding pressure after you switch off. To check a voltage supply at the pump because of a hard start issue after 20 min is the wrong diagnostic route.

 

The fuel pump relay is in Cavity A of the rear SAM. See W203 Wiki. Agree with Russell, Check fuel pressure at the Schrader valve on the front fuel rail. s/b > 3.8 bar or 55psi while cranking.