CLKCLK

So my car won't start, there is no fuel pressure in the fuel line
Fuel pump does not make noise or pump when key is on/crank

I have
replaced new CPS (of course won't fix)
checked the relay (A) and fuse 4 (20). They are all good
already remove the seats and caps to access both left and right side unit

Can both be bad at the same time?
Can someone please tell me how to check for both unit? (which wire should have 12V+ when key is on or crank?)

There are 1 plug on the right (4 wires, brown-red/blue-brown-red/blue) and 2 plugs on the left (1 small-3 wires gray/brown-green/brown-red/yellow and 1 bigger plug-3 wires green/brow-blue/white-blue/black )

Much appreciate!

Rocman8

You are checking the wrong relay(s) and fuse. Those locations are for non AMG. You should have at least 1 but probably 2 fuel pump relays behind side trunk panel on the passenger side. On the passenger side fuel sender connector the Browns are ground and reds are power. 1 set for each pump. They should have battery voltage briefly when turning the key on and constant when cranking.

CLKCLK

I got this voltage behavior, so relays are good regardless. I thought they should stay on all the time when key is on.

I checked relays on the rear SAM driver side. There is anotherone fuse box under the trunk carpet right next to the battery. Did not know there is one on the passenger side?

Thanks Rocman8!

Rocman8

Well it's not actually a fuse box it's more like just an empty space they used to place them. Just because you have voltage doesn't mean the relays and/or wiring connections are good. If the contacts are burnt you may have voltage but under a load it will not be able to carry a current. Access them and check the contacts and replace the relays. You HAVE to start here if you don't have fuel pressure and you do have voltage.

C32owner

If you have voltage when cranking and no fuel pressure then it's more than likely the fuel pump. Just replaced mine

AgSilver

If you have access to XENTRY DAS you can turn the pumps on via the actuation option. It should then be relatively easy to locate the problrm