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No voltage at fuel pump connector?? E39 540i

84K views 27 replies 10 participants last post by  BbradenMmillerW  
#1 ·
Hello all, I need some help. I have a 97 540i and It won't start. I just put a fresh fuel pump relay in, and a spare fuel pump fuse. I pulled the connector from the fuel pump and measured the voltage, I don't get any voltage out of the connector no matter what position the key is in. + white/blue wire, - thick brown wire. I measured the two other pins for the fuel level and I got a good healthy 11.xx volts. What is going on here?? Am I possibly doing something wrong? Thanks in advanced.
 
#2 ·
The fuel pump relay is fused with F31, 10 amps
The fuel pump is fused with F54, 15 amps in your car.

The power to the FP is only there for a few seconds. After you turn the key to start and the engine is running power is there continuously.
Have you tried junping the contacts to keep it running without using the key?
At the FP connector brown is ground and white/blue is 12 volts from the FP relay.

This pic is from my '00 540, yours should be very similar.
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#3 ·
jumping the contacts to keep it running without using the key?
This is a great hint that we don't want to lose so I just added a reference to your post in the bestlinks for future leverage ...

- What are the most often recommended fuel pump & fuel filter brands (1) (2) & a DIY for replacing the fuel filter (1) (2) (3) (4) (5) (6) & a quick test for fuel pump operation (1) (2) and replacing the fuel pump (1) (2) (3) (4) (5) & how to replace and service your BMW E39 fuel injectors (1) & the location of the K96 fuel pump relay (1).

Note: Photo downloaded & shrunk to 640x480 for posterity.

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#4 ·
Ok, thanks jimlev as always. I am not quite sure I understand what you are asking. I have not jumped the relay pins, I need to try that. How do I go about doing that the right way? I will check those fuses again. I just don't get why I don't have power to the pump.
 
#5 · (Edited)
I am not quite sure I understand what you are asking
I think what JimLev is trying to tell you is he understands how the system works, and, if it's doing what you said it's doing when it's doing it, then the procedure he outlined for you should help locate the electrical problem.

For example, he said there are multiple fuses innervating the fuel system - so - the suggestion to you is clear to doublecheck all those fuses. For a list of fuse locations, look here.

By way of example only, here are what 'my' 2002 525i fuses indicate (yours will be different): the point is that there are multiple fuses for the same function so you need to check more than one sometimes.

BTW, I would think a short jumper wire would be used to jumper the pins on a quiet day so you can listen for the fuel pump turning on as you apply the jumper - but I'll let him clarify as I don't know the test conditions.
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#6 ·
Right, just jump the two pins in the socket together with a piece of wire.
 
#8 ·
Hey gang an update. I replaced the relay and checked the fuel pump fuses they are good. So I measured the voltage at the fuel pump connector while cranking and I got 10.8x volts. Is this normal? Also I don't measure any voltage at the connector except while cranking. Is there supposed to be voltage in the other key positions??
 
#9 ·
When you first turn the key to the on position there should be voltage there for maybe 2 seconds, then nothing.
When you turn it to crank you should have 12 volts again.
Your 10.8 volts is low, it should be 12 +volts.
Check the voltage right at the battery to see if it reads 12 volts, which will confirm that it's not your meter reading wrong.
If you get 12 volts (or more) at the battery you could have a bad connecting in the relay socket, the fuse socket, or the fuel pump connector.
 
#10 · (Edited)
For the record, this was posted today, so I pointed the user over here:
Ok I have replaced my fuel pump and my relay and my fuel pump won't come on at turn 2 but it will at turn 3 is there anyone out there that can help really need to figure this out
EDIT:
This was posted today in another thread, which I bring here for cross reference as this is the canonical thread for testing the fuel pump relay:
The fuel pump will only run for ~2 seconds when the key is turned to position 2.
When you turn it to the start position - it will start running again.
When you jump out the relay and the fuel pump starts running did you try to start the engine?
The DME controls the fuel pump relay.
If the engine doesn't start when you jump the relay, check the fuel filter.
 
#11 ·
help

I have the same fuel pump problem.It should work but it isnt .I need to run down the wires fuses relays and the pumps exact location.

Please help I been working in the car 3 days changing eevrything cause it sat a few years.

Its ready... it stRTS when i spray starting fluid.

where is the fuel rail also?

old thrad i know but additional facts will complete it to help manyothrs too

Thanks
 
#16 ·
Yeah, pulled the relay, tested for voltage then swapped the relay for a new one. I still didnt get any voltage at the pump. I'm gonna get another relay today, I'm suspecting the one I tested with and the one that was in the car are faulty
 
#17 ·
Ok so I swapped the relay for a new one, I'm now getting voltage at the harness for the fuel pump but only when cranking the car, pretty sure thats normal. I ordered a new pump so we'll see
 
#18 ·
Out of Curiosity was it the fuel pump?

Last night my 1998 BMW E39 528i started, ran rough and then died, I started it again, and it barely started and died, now it cranks over and doesn't appear to even try start at all so I am hoping it's just a fuse or a relay and not the fuel pump. Earlier that day, and all week it was running fine, and not even missing after cleaning the grounds last week.

My 15 amp fuse for the fuel pump in the trunk is not burnt, and has power but the car all of sudden won't start. I also have no computer trouble shooting codes using my Peak Research reader. I'll jack up the car and verify if the fuel pump is pumping gas by disconnecting the filter, but I can't seem to hear it running.

I am stranded in San Luis Obispo, so any help would be very much appreciated.

The unemployed IT guy!
Jose F. Medeiros
408-256-0649
http://www.linkedin.com/in/josemedeiros
 
#19 ·
For the record, this thread came in handy today for the thread below:
> E39 (1997 - 2003) > Fuel relay location

Location of fuel relay on a bmw e39 1997?
Just type /relay f3 in the bestlinks.
- One user's attempt to locate, describe, and photograph all fuses and relays in the BMW E39 with a picture of every fuse & relay (1)

The OP's job is to add value to that thread!
I have checked all the fuses and relay that I know of unless someone knows of other relays someone all seem to be okay but still no power to the fuel pump any answers or help.
Did you run the fuel-pump relay short test?

Typing /fuel pump f3 in the bestlinks nets a lot of good threads, e.g.,
- How to test for fuel pump operation (1) (2)
See also:
- How does the E39 fuel injection FI system work (1) & the location of the K96 FPR fuel pump relay (1) & the location of the fuel system pressure test Schrader valve for the I6 (1) and V8 (1) (2) (3) & a quick test for fuel pump operation (1) (2) & what are the most often recommended fuel pump & fuel filter brands (1) (2) & a DIY for replacing the fuel filter (1) (2) (3) (4) (5) (6) (7) & a DIY for replacing the fuel pump (1) (2) (3) (4) (5) & how to service your BMW E39 fuel injectors (1) & how to replace the 7.52X3.52mm and 9.2X2.8mm fuel injector o-rings (1) & cleaning the fuel gauge sensor (1) (2) & replacing the fuel sensor (1) & resolving blown fuses due to a stuck fuel filler door solenoid (1)
 
#20 · (Edited)
This was posted in the tandom-jobs thread, but it really belongs here ...
I am having a starting problem and I'm thinking Fuel Pump and Filter (why not do both at the same time?) the car is in access of 150k, right? The reason I'm directing this question to you is because you mentioned Schrader valve, on top of the M54 engine fuel rail. If I suspect my fuel pump to be bad or my filter clogged, wouldn't it be reasonable to start testing at this VALVE by pressing it down to see if there is fuel pressure? I do NOT mean measure the pressure but if there is NO pressure AT ALL wouldn't that be a sign of NO FUEL so NO START? Would it be wise to have someone crank the engine while pressing down on the Schrader valve and shouldn't fuel come gushing out??? Just an Idea, naturally I would have to take precautions.
I've been through several of the best links and I've seen this particular post before. However my car seems to have a different configuration.

Here is is pic of my Relay Panel in the Trunk.
Which Relay? I have 3 to chose from.
The one in your link appears to be for a Wagon.
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#22 ·
Pudl kindly informed us, in the canonical relay thread, that the answer to the prior question was already in the record:
...already answered the question in post #2 of the fuse and relay thread.
-> E39 (1997 - 2003) > Picture & amperage & description of every single fuse & relay in the BMW E39
I'll start putting the relays here so this post #2 is a work in progress (WIP).

There are (up to) 41 relays? in 3? relay locations in the BMW E39:

  • Passenger side engine bay ebox <== ABS, wipers, fuel injectors, DME, AUX, SAP
  • Behind the glove box <== fuel pump (after & including 2001), blower motor,
  • Battery compartment in trunk <== fuel pump (before 2001), unloader, defogger, central locking, fuel door lock actuator?
Let's list all the relays we can:

  1. K? = aux fan relay (1)
  2. K4 = interior heater blower motor relay (1)
  3. K5 = does not exist
  4. K6 = headlight cleaning relay (1)
  5. K? = starter motor relay (1) (2)
  6. K13 = rear window defogger relay
  7. K36 = first wiper relay (1) (2)
  8. K37 = second wiper relay (1)
  9. K96 = fuel pump relay (1) (2) <== location changed in 2001
  10. K? = wiper relay (1)
  11. K? = unloader relay (1)
  12. K? = ABS control module relay
  13. K6304 = secondary air pump relay (1) (2)
  14. K? = fuel injector relay
  15. K? = DME relay
  16. K? = fuel door lock actuator (2)
  17. K? = ?
Let's annotate the pictures (in the end, we should clean this section up to have only a few pictures with all the relays labeled).
WIP: Right now it's a mess as I gather up the relevant photos.

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#26 ·

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#25 · (Edited)
While there are multiple diagrams of the relays behind the glovebox, I didn't see any clear photos of those relays in the aforementioned thread:
> E39 (1997 - 2003) > Picture & amperage & description of every single fuse & relay in the BMW E39

So, I ask either others who have a picture, or bem-ster who will likely be opening up the glovebox area to test the fuel pump relay, to snap a picture of the relays shown in the diagrams so that we may annotate that picture, so that others stand on his shoulders in the future.

This diagram shows the kind of shot we need of his relays (which we can then annotate):
Image
 
#27 ·
I'm going through a probable GM3 (General Module III) quagmire at the moment. I have the typical no central lock, no interior lights, no power windows or power seats (except drivers only), no trunk button, no key fob activation. What's more troubling about mine is my car will NOT start. It cranks, but the fuel pump is not pumping thus no fuel to injectors. I have a feeling that my GM3 got fried and set off the Anti-Theft Drive Away Setting (the car suddenly shut down and alarm went blaring at 40mph the other night). So I'm worried, but I'm in the midst of checking the FP Relay and have some pics to share while I have my glovebox and related guts pulled out. Here are the pictures of:
1) General Module III (GM3) - The long rectangular white box with the silver metal heat shield.

2) Fuel Pump Relay - I have a 2002 525i. My FPR is here behind the glove box.

3) Fuel Pump Relay Connector - Tall black relay style box. Looks just like the FP Relay except it's twice as tall and is black.


It was a huge huge huge pain to unbolt the plastic tray holding the GM3 and the Relay "Rack", and then to unclip the relays off of the rack. Very tight space, no room, sharp edges under there. I removed the glove box first.

If anybody has any tips or info about this possible Drive Away Program of the ZKW (GM3) please let me know. Thanks in advance!