HELP Fuel Pump Relay EKP/Engine Wiring Schematic

[gheorghe]

In this case, OP measured pin11 of DME and no 5v or higher to turn on the pump relay.

OP, disconnect the relay (in the trunk) connector, then measure Connector pin1 (or DME pin11) when turning on ignition. In case the relay was shorted it could short out pin11.

I just measured the voltage with the relay disconnected and I see 0.01V at the EKP pin 1. When I hook the relay back and re-measure, I see 0.03-0.05V. I see this voltage till the ECM relay kicks off and then the voltage goes to 0V which I expect.
If anyone would be able to back probe their EKP relay pin 1 under a couple circumstance (engine off key in position 2 and engine running) it would be a huge help.

[gheorghe]

I've seen the coil ground loose in the past and it cause the EKPS to fail. Car was in the shop for a valve adjustment, came back on the tow truck with a crank no start. EKPS was replaced and the car left, came back a while later same issue crank, no start. EKPS was dead again... further diagnosis found the ground wire was loose. The ground was tightened and the EKPS replaced again, car didn't come back.

Hi George, thanks for the heads up, it confirms the fuel side of the vehicle is affected by missing this ground. In my case, I do not know how to fully test the EKP but I have tested everything around it and I am leaning toward the DME as being the cause. I have continuity from DME X60002 pin 11 all the way back to the EKP pin 1 (same wire). I can manually prime the pump by jumping pin 6 and 2 on the EKP and start the car but I am not getting more than 0.5V on PIN 1. With the Key in Position 2 fuel pump does not prime.
Actually, priming the car manually by jumping the pins caused something interesting this weekend, typically doing this will start the car for 10-20 sec and then die off, but during one test, the car stayed running. I was able to back probe pin 1 at the EKP and the most voltage I was able to see was 1.2V with the car running. I known this is a PWM signal but I was told pin1 at the EKP should have at least 5V when there is signal from the DME.
Can anyone confirm with a DVOM what voltage they see at the EKP Pin 1 when they put the key in Position 2 before starting and what voltage they see when the car is running?

[sapote]

In this case, OP measured pin11 of DME and no 5v or higher to turn on the pump relay.

OP, disconnect the relay (in the trunk) connector, then measure Connector pin1 (or DME pin11) when turning on ignition. In case the relay was shorted it could short out pin11.

[George Hill]

I've seen the coil ground loose in the past and it cause the EKPS to fail. Car was in the shop for a valve adjustment, came back on the tow truck with a crank no start. EKPS was replaced and the car left, came back a while later same issue crank, no start. EKPS was dead again... further diagnosis found the ground wire was loose. The ground was tightened and the EKPS replaced again, car didn't come back.

[gheorghe]

Looks like I might have been a bit too excited. I just measured for voltage right at the X60002 connector pin 11 and I get 0V with the key on. Looks like I need to look for a place to repair my DME or a new DME

[sapote]

Thank you for the great info guys! I have it narrowed down to the EKP.

EKP Pinout results:
Pin 1: DME signal from X60002 PIN 11 - I have 0.5V with key ON
I know the pump works if I jump it and since I am not getting anything out of Pin2 I am lead to believe the EKP is bad.

Pin 1 should be 5v (or 12v I'm not sure) to turn on the relay during pump priming or running. If engine not running then pin1 is logic high (5v or whatever higher) only a short time priming. So something is wrong: either the DME pin11 output is bad (zapped by ignition high voltage event) or the wire from DME pin11 to relay pin1 is opened or shorted to other conductor.

1) try to check continuity from relay p1 to dme p11 with long test wires, or
2) disconnect the wire at DME pin11, then measure pin11 when key turned on; should be 5v or higher, momentary, if not, looking for another DME or repair it.

[Lukem3]

Thank you for the great info guys! I have it narrowed down to the EKP.

EKP Pinout results:
Pin 1: DME signal from X60002 PIN 11 - I have 0.5V with key ON
Pin 2: Signal to fuel pump I get nothing - should be ~12V
Pin 6: I get the correct 12V battery voltage
Pin 7: Ground
Pin 8: I have 12V with key on

I know the pump works if I jump it and since I am not getting anything out of Pin2 I am lead to believe the EKP is bad. I did take the black cover off the EKP thought and I didn't see anything burned or dark inside. The capacitor is also not bloated or showing signs of damage. I may have damaged one of the microchips inside running the car without the ground???

I'll see if my local BMW dealer has one in stock, fingers crossed.

Dme signal voltage should be around 5v. If you're getting 0.5 volts you either have a burnt wire or a burnt dme, the relay won't actuate and send power to pin 2 without the confirmation from the dme with 5v

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[gheorghe]

Thank you for the great info guys! I have it narrowed down to the EKP.

EKP Pinout results:
Pin 1: DME signal from X60002 PIN 11 - I have 0.5V with key ON
Pin 2: Signal to fuel pump I get nothing - should be ~12V
Pin 6: I get the correct 12V battery voltage
Pin 7: Ground
Pin 8: I have 12V with key on

I know the pump works if I jump it and since I am not getting anything out of Pin2 I am lead to believe the EKP is bad. I did take the black cover off the EKP thought and I didn't see anything burned or dark inside. The capacitor is also not bloated or showing signs of damage. I may have damaged one of the microchips inside running the car without the ground???

I'll see if my local BMW dealer has one in stock, fingers crossed.

[Lukem3]

DME Connector X60002 PIN 11.

That would be for an earlier build car, 2006 is showing pin 10

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[Pnick]

DME Connector X60002 PIN 11.

[sapote]

See this thread that we discussed about the US fuel pump relay to help you trouble shoot it:

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/92305-power-to-fuel-pump-but-no-prime-any-help-please/page2

[gheorghe]

https://drive.google.com/folderview?...W45sf3pc43K4jN
Wiring diagram of dme along with fuel sender to the cluster. Goodluck friend

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Thank you sir!!! Very much appreciated!

[Lukem3]

https://drive.google.com/folderview?id=15y6e1W8jFe4cX5vFQJW45sf3pc43K4jN

Wiring diagram of dme along with fuel sender to the cluster. Goodluck friend

Sent from my SM-G996U1 using Tapatalk

[gheorghe]

I've narrowed the issue down to fuel.
My fuel pump is not priming but it will turn on if I direct jump it. I can actually start the engine and run it with the fuel pump directly jumped. This tells me the injectors and ignition coils are ok.
I'm now on the search to see why the fuel pump is not turning on by itself.
- I checked fuse 54 - good
- checked the green fuel pump relay- good
- I don't know how to check the EKP Relay though, but I will back probe to see if it is getting power
- I also checked all the fuses in the black box under the DME cover and all 5 are good
I'm still wondering if the DME is sending a signal to turn these components on but I couldn't find the pinout chart to see which pins send power to the EKP.

[sapote]

I'll check to see if I'm getting fuel next.
.

How to find out?
Hear the fuel pump prime? Key turned on, one pin of the injector should be 12v, and the other pin should be switching between 12v and 0v alternately when cranking.