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      11-01-2013, 10:49 AM   #24
Synergy
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Drives: Jet Black E92
Join Date: Apr 2008
Location: San Jose, CA

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Quote:
Originally Posted by michbmw View Post
not that his isn't something you already have (should be in your Bentley) but this is the wiring schematic for you car, I'm not sure why the combined the two wire connectors into a singular one like your car has but the red with white stripe (positive) and brown (negative) your two wires. if you don't see any voltage there then I suspect it has to be the EKPS (fuel pump control module) that is bad. for a sanity check I would disconnect the connector at the EKPS and check continuity with the wires just to make sure there isn't a break or short in-between. Something else you can try (not that I really recommend this) is to put 12V from another source on the red/white wires and brown wire then try to start the car to see if it starts, if it does you'll at least know your pump is good. voltage is supposed to be 12.6V so something close to 12 should work. though beware of amperage, it is only supposed to be between 8-13 amps, too many amps and you'll cook it or worse, not enough and it may not work
It's funny you posted this, because I tested this last night and didn't get a chance to update my thread yet

So here's what I did:

Since I found out there was no power on the red/white wire that plugs directly into the fuel pump, I figured there was an issue with a fuse or relay. I ripped out my rear bolster for the passenger side and started probing the EKP module for 12V. I found there was ~11.5V on the "input" side, but nothing on the "output" side going to the fuel pump.



Here's the "output" side, which goes to the fuel pump. These wires showed no voltage.



Then I removed the module from the car and brought it inside, hooked up an external 12V power source directly to the input side and probed the output side again. Nothing. I found the pinout diagram for what appears to be an IC (Infineon chip PN: BTN7960) and started probing every pin for the proper values. I found that one of the pins was not receiving 12V (either pin #2 or #7 on the chip). The chip is located top center, near my ground.



I flipped the PCB over and removed the rubber pad...and found a big brown spot! Looks like this chip burnt out



So now that I know this chip is burnt out, I can confirm my EKP module is definitely bad. Is this the reason why I don't have power to my fuel pump? Definitely. Will replacing the EKP resolve my car not starting issue? Possibly.

I ordered a replacement EKP on eBay, used, but I'll need to code it? First thing I'm going to do when I get the replacement unit is to test it for power and make sure the hardware is 100% functional. Then I'll worry about the coding afterwards.

michbmw, thank you so much for your help. I'm very appreciative and grateful to see you help a complete stranger, especially when you're not getting paid for it
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