james clk430

OK so long story short I drove my car last night ran great haven't drove it in about 2 weeks went to get gas and some food so I can drive it 2day went in the garage to get ready to go and no start it tries but won't start I thought maybe the battery was low so I tried to jump it nothing I change the crankshaft position sensor nothing I checked all of the fuses in the trunk dash and hood nothing all seem to be fine I check the connections on the battery everything is solid I've had 3 people look at the car and no one can figure it out I need help ideas anything I'm lost

burgca

James, you can look at the following for possible issues, but it could be you bought a bad CPS

http://www.mercedesmedic.com/mercedes-wont-start/

More guidance on checking fuel pump and pressure
https://mbworld.org/forums/clk-class...not-start.html

Good luck

Zavato

Punctuation is your friend.

james clk430

Okay so I found out that I have zero power to my fuel pump when I hook it up to a 12 volt battery the fuel pump works great it's also a brand new fuel pump I tried the fuel pump relay under the hood on the driver side with all of the fuses and I still have absolutely nothing so brand new fuel pump brand new fuel pump relay and I'm getting no power to it what else could it be I really need some help here it's a 2001 Mercedes Benz CLK 430 also when the fuel pump was hooked up to the car I took two wires for the negative and positive hooked it up to the fuel pump and the car starts perfectly fine I just can't have two random wires going from the fuel pump straight to the battery of course is there a fuse I'm overlooking or is there something I'm missing idk what else 2 do......

Serndipity

Sounds like a possible issue with:

Voltage supply from engine control module (N3/10) is missing.
Malfunction of drive authorization system (DAS) .
Fuel pump electrical wiring circuit defective.

Couple of suggestions:

Best way to check fuses is with a multi-meter, set to read voltage. With the negative lead to ground, on the top of the fuse, with the positive lead, test the metal contacts on the both ends for 12 volts. This method enures that the circuit has voltage input and that the fuse passes it through. Note: Just looking in the fuse window is not sufficient, as the fuse contacts may be corroded, due to dissimulator metals in contact (e.g. specially in high amperage circuits).

You can also probe the relay socket with the volt meter. The relay has 2 circuits. The diagram of the circuits and associated pins should be diagrammed on the relay's cover. The engine control module should power the control circuit (i.e. coil). With the relay removed and the key turned to the position where the fuel pump should be operating, there should be 12 volts present on 1 of the 2 socket connections. The side with no voltage goes to ground, which then can be checked with the meter set to read ohms. Similarly, the other 2 socket connections, that switch high power to the pump motor, can be checked as well.

exhaustgases

I'm curious would the alarm system shut off the fuel pump? Also do these cars have a collision inertia switch that shuts off the fuel pump. All those could also be the cause of this problem. And please let us know what it was when you figure it out.

james clk430

Thank you very much I'm going to be checking everything right now its just so crazy that it would go out like that this car I've owned 4 about 5 years now and this is the only prob it's ever had I hope I can find something out cause this sucks

james clk430

Okay so I have literally done absolutely everything to my ability to find out why I'm getting no power to the fuel pump I saw a cool YouTube video where this chick took a piece of wire and put it in between the relay and where you put the relay in I tried to do that and there is absolutely no power going to wear the relay goes I have literally chased down the wires all the way down to the front of the car I don't see anything touching no wires burnt anything I took a multimeter and checked everything there's just no power getting to the relay I think I'm going to have to take it in I'll let everybody know what the problem is when I find out

exhaustgases

The main problem is lack of information. With out a wire diagram we are all helpless.

MarcusF

The WIS has wiring harness diagrams. They're color correct and VIN specific.

A1EK

When you checked the power to the relay, did you do this with the ignition on obviously?

I had a similar issue where the car would crank and crank then eventually start. Turned out to be dirt between the relay contact inside the cover. You could try opening the relay black cover up and sliding a piece of fine sand paper between the contact points to clean them inside.

james clk430

So I took it to a shop and nobody knows what the hell is wrong with it what,a wast of $300 there is just no power going to wear the relay plugs into in the boot I mean my side panels are off on my car all the way to the front of the car I don't get it one day runs great and not even 8 hours later it won't start it's garage kept taken care of ect it sucks does anyone know of a good electrical guy in Denver Colorado

james clk430

Yes I did it with it on the sec pos and try ed turning the key ect I'ma try that trick you mentions about cleaning off the connectors I'll let yall know what happens

insame1

I took my car in for an interment non start (clk430). Star wouldn't see the fuel card. He took it out and put it back and boom. I never had the problem again.

Serndipity

In post #5, I suggested possible issues and what/where to check.

As suggested, if the relay socket is not getting either the required control voltage or the switched contacts, that provide 12 volts down steam to the fuel pump, would would go a long way to isolate your fault.

Did any of the shops check for stored diagnostic trouble codes, using the MB Star Diagnostic System?

If so, forward the DTCs along, because it will would have suggested further DIY trouble shooting and repair measures.

exhaustgases

So was the shop a Mercedes shop? Or dealer? It is a waste of $300. going to a shop that knows nothing about Mercedes stuff.