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Discussion Starter #1
1/2000 E39 M5, (205,000km) or 125,000 miles

Went to drive home from work and no go, cranks fired and died immediately, tried it a few times of course, now just cranks and no fire.
!. Had roadside assistance man put head on back seat and switch on key, couldn't hear the pump running... Aussie cars dont have clutch switch btw.
Haven't tried the relay bypass yet, fuel pump was new about 5 years ago.
2. Tried 2 spare keys in case it was an EWS out of sync, no go.
Should new oem pumps last more than 5 years? Had new filter at same time.
Will start diagnosing tomorrow.

Had ignition switch fail a while back, pulled it apart and filed the contacts and reassembled, has been fine since.
Could that be suspect?
WIll start with pump, see if fuel is being delivered, then check relay with bypass procedure.
NO Peake codes showing up.btw..
 

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Certainly sounds like the pump. I'd jumper the relay and go from there.
 

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Pump, then battery. Most likely pump.
 

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Discussion Starter #4
Certainly sounds like the pump. I'd jumper the relay and go from there.
1/2000 E39 M5, (205,000km) or 125,000 miles

Went to drive home from work and no go, cranks fired and died immediately, tried it a few times of course, now just cranks and no fire.
!. Had roadside assistance man put head on back seat and switch on key, couldn't hear the pump running... Aussie cars dont have clutch switch btw.
Haven't tried the relay bypass yet, fuel pump was new about 5 years ago.
2. Tried 2 spare keys in case it was an EWS out of sync, no go.
Should new oem pumps last more than 5 years? Had new filter at same time.
Will start diagnosing tomorrow.

Had ignition switch fail a while back, pulled it apart and filed the contacts and reassembled, has been fine since.
Could that be suspect?
WIll start with pump, see if fuel is being delivered, then check relay with bypass procedure.
NO Peake codes showing up.btw..
Thank you to technician and silent for your replies and help.
Update:
  • Jumped relay with paperclip, which got very hot...
  • Pump made no sound
  • swapped in spare 540 pump I used to get going last time, (ran it for a month till I got new pump in from USA)
  • Still no start and no sound at key on from the spare pump.
  • Put volt meter across blue/white power and brown ground terminals on pump harness, no power at key on.
Where to from here?
 

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Thank you to technician and silent for your replies and help.
Update:
  • Jumped relay with paperclip, which got very hot...
  • Pump made no sound
  • swapped in spare 540 pump I used to get going last time, (ran it for a month till I got new pump in from USA)
  • Still no start and no sound at key on from the spare pump.
  • Put volt meter across blue/white power and brown ground terminals on pump harness, no power at key on.
Where to from here?
There is a fuse in the trunk by the pump relay. I don't remember which one or the amps but check for any blown fuses back there.
 

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First things first, there are two systems, one uses a standard relay and one system uses a electronic control device. What system do you have in your car, a standard looking relay, light blue or green IIRC or a bigger black control relay?
I would be cautious here because of your findings, you might have a short in the wiring and sparks and fuel vapour don't mix well.
The paper clips do get hot when jumping a relay but hot is subjective. I am concerned that your "working" pump did not run. Pull it and bench test it and see if it runs, if it does be more cautious if it does not run then that would explain the hot clip and you can be less concerned, but I would still be gentle. Might as well check the first pump while you at at it, if it also runs your issue would likely be in the wires ans caution would be advised.
I would look for a short to ground with the lid on the tank and power off everywhere. Unplug the pump plug and secure it so it can't touch anything, unplug the relay find the power wire that goes from the relay to the pump. Use ohms with one lead in the wire and one lead going to ground if it says 1 then at least you don't have a short to ground. Just for extra check do the same at the pump plug in case there is something weird. Next check the path from the pump to ground and you should get a solid zero depending on scale of your meter so turn it to the lowest then check one scale higher until you have exhausted all scales. If the ground wire was 90% broken that could prevent the pump from running although is not supported by the hot clip, but just do this to open your eyes and be sure.
This is the only wiring diagram that I have it is for the system with the black relay.
It is two drawings main power to the relay and the relay pump diagram.
932991
932992

Use F54 as your reference to combine the 2 diagrams.
 

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Discussion Starter #8
Thank you to the board and loyal members/contributors....
Think it is solved:
  • Bench tested the pump I removed, and it ran fine.
  • this is how the Australian cars look in the trunk.
  • Everything or most of what I have found on line said
the second relay was for the fuel pump- so thats what I jumped to test the pump.

* Looking at the wiring colors on the relay plug and the pump plug it is actually the first relay.
A blue and white power wire.
* So I jumped the first relay and I can hear the pump going.
Am off to find a new relay and see how it goes, and will put the M5 pump back in.
Just hope I havent damaged what ever that second relay controls when I jumped it and got a very hot paper clip.


933006
 

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So yours is like the early Brit cars and there has been an issue with them. My memory sucks but I do remember on a few that it was a wire issue. Grab any of those relays and replace the fuel pump relay. There is at least one that will prevent the car from starting, might be the unloader relay for the ignition so you might have to try all of them. If none allow the car to start then you might have the same problem that other Brit cars have and we will have to find one of those posts, because I don't remember the issue. I think it was the path back to the ground or DME.
My other computer has some Euro car issues on it and I leave for the east in two days + two days of driving.
 

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Discussion Starter #10
Sorry guys but this gets sillier..

I checked all the fuses closely.
I checked again before I left to go and get a new relay.
They all look intact to me.
With the relay fuse 54 in the trunk , 25amp, i pulled it out again and I noticed:
* a slight blackening on one side of the plastic close to the spades,
So, I decided to change it anyway.
Damn thing started straight up.

SO now what has caused this to blow?
Am I a time bomb till it goes again?
The pump is 5 years, and 75,000 km
Should I just get a new one?

Only recent work was the ignition switch went crazy, lost steering wheel controls, radio, interior light going on and off by itself...
pulled it and disassembled, filed the contacts and refitted, been good for a month, still no issues.

Salior, technician, silent, NFS021, Sorry for the false alarm.
and I Didnt enjoy changing pump in and out twice either...
 

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Discussion Starter #11
Sailor.. timelines askew here.. just saw your reply,

yes this car had strange ground wiring issues with harness from vanos to DME couple years back, was a corroded join in a sealed up junction.
Will try a search on wiring issues..
 
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