Next time you go for a drive pull up test 9 in the OBC and see if the volts drop below 13.3 volts. It usually happens when you lift off the throttle but it can be at any time.
It is a module but it does not work that way. They did not use any part of the module except for the relay which is truly just and on off switch and they used a resisted pin out that is connected to the output for the pump which it uses to know there is power going to the pump. That is how the DME knows the pump is on. If the pump draws too much power it may drop the volts to the DME which also throws the relay code.
When did you last clear all of your codes? You do have a couple of errors on the same circuit. I will look at the WDS tomorrow. I also don't see any I ran out of gas codes 81 and or 95.
The relay closes and the pump is feed by fuse 54(iirc) and is alternator voltage always not less, while running. A relay is a control winding that gets voltage, creates magnetic field that closes a switch. It is very simple. Measure the volts at fuse 54. The other thing you have to understand is voltage drop and how it works with your digital volt meter. Where specifically did you hook up your meter?
Next time you go for a drive pull up test 9 in the OBC and see if the volts drop below 13.3 volts. It usually happens when you lift off the throttle but it can be at any time.
It is a module but it does not work that way. They did not use any part of the module except for the relay which is truly just and on off switch and they used a resisted pin out that is connected to the output for the pump which it uses to know there is power going to the pump. That is how the DME knows the pump is on. If the pump draws too much power it may drop the volts to the DME which also throws the relay code.
When did you last clear all of your codes? You do have a couple of errors on the same circuit. I will look at the WDS tomorrow. I also don't see any I ran out of gas codes 81 and or 95.
The relay closes and the pump is feed by fuse 54(iirc) and is alternator voltage always not less, while running. A relay is a control winding that gets voltage, creates magnetic field that closes a switch. It is very simple. Measure the volts at fuse 54. The other thing you have to understand is voltage drop and how it works with your digital volt meter. Where specifically did you hook up your meter?
Joe take your old relay apart and post pictures.
Right at the fuel pump. Voltage drop doesn't have any affect on the current situation anyhow, and besides, you saw the numbers and also menu on the cluster showing 13.8 (matching the high end of the fuel pump). I was simply using that video to show that the voltage is varying exactly when the pump sound varies. So this was making me rethink my relay being good, because if it is a module, (and not just a switch) then it could be why when I was sitting broken, I could hear the pump, but not getting enough "juice" to give the proper pressure to fire up. It would always try to start with a cough or a sputter, but no firing up to run. It was not just sitting turning over with nothing happening, in other words.
Has anybody else done a voltage test at the pump? If so, you should also run one. Also of note, which I tried to show in my overly long video, the cars voltage never did drop, but I will check that the next time I'm out on a drive (tonight).
Edit: also, when I do clear the codes, they stay gone, mainly, but there are quite a few timeouts and the whole knock sensor thing, that come up when the key is on for a long time and car is not running, evidently. I can clear them (note that the pic was taken on the 4th) and then go for a drive and run them again, but I will upload another if I have a pic of when they were cleared.
You want to fantasize about how this pump works go ahead. I have not seen one engineering fact to support it. If I wrote a report like you are pontificating to one of my bosses I would be fired. Live with your broken car, mine works fine. Show me your proof it is not a switch. You don't think that maybe damaged contacts on the switch could limit the voltage? You don't think that a plugged fuel filter causing to much electrical current to flow thru the contacts to the pump could cause damage? No no it is none of those things. I think the gerbil that controls the brake on the fuel pump is getting lazy you need to add sugar to your gas to give him more energy to do his job.
So you put the two leads on right at the pump one on neg and one on positive.There are a lot of reasons you could see 11v, fuel filter and or relay are the most likely candidate. But of coarse I gave you the test to see already. One of the basics in auto repair is to replace the fuel filter when you replace the pump. You are yet to do that. Stop screwing with this and put the filter and the relay in. If you really want to know what it is go take a coarse in auto tech first or of coarse you could just do the tests. I don't know how many times people have told you to do some voltage tests, and then there is the fuel pressure test still not done. Stop driving the car around and test it or put those 2 parts in.
Sailor - you are one of the most helpful people on this board who very obviously gets annoyed when someone doesn't promptly follow your (sound) advice
AFAIK, he's waiting for the fuel filter and relay right now, so he's following that advice. He hasn't jumped the relay yet, but he may have been waiting for it to die again before trying that. In the meantime, he's measuring voltage and doesn't appear to have a gauge to measure fuel pressure. Dude, he's not ignoring you
...
Bibledriver - the fact that you have coughing and sputtering was news to me....didn't realize that. Sounds fuel pressure related now, which could still be electrical but seems less likely. As said, I'd still recommend doing the relay and filter because they are a combination of good maintenance and an easy to replace and inexpensive part that weirdly fails on these cars after a decade (the relay), but then I'd start suspecting the fuel pressure regulator.
FIRST off, Chill, and realize that I am not sitting on a throne here, I am in a humble position trying to learn. I will do a fuel pressure test, but to maximize my efficiency, as I am a bit busy, I figured I would just do a before and after once I get the filter (that would answer questions).
I found it interesting that the fuel pump pitch varied, and there is not a lot of way for you to argue that dirty contacts would magically allow more current once the engine speed reaches a certain level. The only reason I checked this out is because IF the relay is not just a relay, it then becomes part of the diagnostics, and it is not as easily ruled out.
Also, as for my technical background, don't presume to know that I have none, as this is FAR from the truth. I am learning a new-to-me car, I have a lot to learn, and am simply asking questions to gain knowledge. The whole point is that I don't have proof of the source of the problem. I am not attached to an argument, only what I am observing. What I have discovered is perhaps contrary to some of your views, but there is only information to glean from it. As I asked, have you, or anybody you're aware of, done the voltage test so that I can compare?
Whatever voltage tests you want me to run I will. I will drive the car tonight and report my experience, if you're talking about the car voltage dropping on decelleration, as I understand you.
And trust me, as soon as I get the filter (which is ridiculous in and of itself, as it was ordered May 31), it will go in. Otherwise, I still feel the pump should be no worse off than the one that I replaced. This is my whole issue, and is why I lean toward the pump.
Trust me, I am wanting to get it repaired, and it is a bit frustrating. Diagnosing when failing is easy. This is not in that category. Everything checks out when running, and when not, I am certainly not going to dig into gasoline with the highway whizzing by at 80mph 10 feet away.
Sailor - you are one of the most helpful people on this board who very obviously gets annoyed when someone doesn't promptly follow your (sound) advice
AFAIK, he's waiting for the fuel filter and relay right now, so he's following that advice. He hasn't jumped the relay yet, but he may have been waiting for it to die again before trying that. In the meantime, he's measuring voltage and doesn't appear to have a gauge to measure fuel pressure. Dude, he's not ignoring you
...
Bibledriver - the fact that you have coughing and sputtering was news to me....didn't realize that. Sounds fuel pressure related now, which could still be electrical but seems less likely. As said, I'd still recommend doing the relay and filter because they are a combination of good maintenance and an easy to replace and inexpensive part that weirdly fails on these cars after a decade (the relay), but then I'd start suspecting the fuel pressure regulator.
Thanks, and I will be ordering a relay too, at this point; especially after my findings last night of varying voltages. It is a bit confounding and I would love it if the car was just sitting in my garage dead. That would be quite easy. Onn the other hand I could just by everything related, but that is not my style to just throw parts at it unless they are necessary or know to be problematic.
I am chilled sometimes you have to yell to make people listen. This has been going on for over a month now. On May 12 tradin1 told you fuel filter. Right or wrong it is/was/should be the first diagnostic thing. This is not a throwing parts thing unless you know when the last fuel filter went in it is simple maintenance.
End of May you jumped into another thread where I was miffed because a guy did not take someones very sound advice and follow Joes Diy that fit the circumstance perfectly. That was on its second or third day of no results. So I yelled a bit he listened and in a few minutes of following Joes DIY he had a full diagnostic done and knew what was wrong and it was his fuel pump, which is what the DIY is for.
This has now gone on two more weeks and you saw how effective that was but you think yes relay then no relay but you still have not pulled the stupid relay out and replaced it with a piece of wire or paper clip to see how your pump works and diagnose your fuel pump relay.
You asked me in that thread, I took the time to read all your threads on this topic, I did and replied to you. Lots of other people have given you advise because you have asked, but it sort of seems like you have ignored it all. Frankly it is a bit rude. It is really hard to be the person trying to help because we don't have the car, you do so the people ask for little tests to better understand, but you know it will help you understand also.
Whether this module is magic or not I don't care if you pull it and put the wire in and the pump fluctuates it leaves plugged filter or something else putting resistance on the pump or an electrical problem in the car.
I am chilled sometimes you have to yell to make people listen. This has been going on for over a month now. On May 12 tradin1 told you fuel filter. Right or wrong it is/was/should be the first diagnostic thing. This is not a throwing parts thing unless you know when the last fuel filter went in it is simple maintenance.
End of May you jumped into another thread where I was miffed because a guy did not take someones very sound advice and follow Joes Diy that fit the circumstance perfectly. That was on its second or third day of no results. So I yelled a bit he listened and in a few minutes of following Joes DIY he had a full diagnostic done and knew what was wrong and it was his fuel pump, which is what the DIY is for.
This has now gone on two more weeks and you saw how effective that was but you think yes relay then no relay but you still have not pulled the stupid relay out and replaced it with a piece of wire or paper clip to see how your pump works and diagnose your fuel pump relay.
You asked me in that thread, I took the time to read all your threads on this topic, I did and replied to you. Lots of other people have given you advise because you have asked, but it sort of seems like you have ignored it all. Frankly it is a bit rude. It is really hard to be the person trying to help because we don't have the car, you do so the people ask for little tests to better understand, but you know it will help you understand also.
Whether this module is magic or not I don't care if you pull it and put the wire in and the pump fluctuates it leaves plugged filter or something else putting resistance on the pump or an electrical problem in the car.
Just so you know, I was listening before you yelled, for what its worth. The post above your yelling was actually me responding to your requests!
OK so, also, I appreciate a HUGE amount the help i've received and am thankful you read my posts.
Yes, I should have replaced said filter, MY fault, and I take the beatings for that. (still I expect more from a high performance pump than stock. dont you?) I have been waiting and waiting for this filter and am about to make a yelling phone call myself! Finding a non OEM pump in the tank makes me think filter is perhaps not new.
also, I am unfortunately not broken, and not the normal mold of broken when I AM broken. I deal with diagnostics daily, though you don't know me, I do ok at troubleshooting. It is not as good of a fit as joe's situation, as I am not broken. I am working, and intermittently die. I get activity from the pump when dead, but IMO, not enough (which is why my hunch of bad pump). I can almost promise it is NOT fuel level related.
Maybe the extra volume is simply exacerbating a collapsing media in the filter and when collapsed, blocks flow for the most part. Electrical is ruled out.
I can jump the relay if you like. I also am curious if we are sure that the Voltage at the pump should be consistent or should fluctuate. What do we have other than "what I understand" to confirm which is true? I already asked you if you know of anybody else testing it that way, and of yet no response. Also, if I simply put a hot source to the pump, sure it will spin, just like it is now. (Don't get upset, I must have an understanding of our goals). So are there any wiring gurus that can confim the source of power to the pump is simply from the battery when the relay closes the circuit, because there are mixed opinions on this. This is partly why I posted the vids. Shoot, I really would love to see somebody else measure the power at their pump. This would help a ton.
This is all about learning, and I don't think this situation is run of the mill, unless it is a funky regulator as mentioned above.
What other tests is it I need to do that will provide help.? Not trying to be rude and I think, sometimes after reading posts, it get a bit jumbled with my own thoughts, not intentional.
I think my concern is that I replace the filter, good to go for a few thousand miles, but it masks the weak pump problem I suspect to be evident (only thing that has changed, simplest explanation) until it is too late and I have to eat the cost of a new pump along with the pain in misdiagnosing.
I am going to jump the relay, but not quite sure how much that will offer, and also remove the underbody panels to visualize the filter for make/originality.
Rambling , sorry, SUMMARY
Assessment
1.Filter
2. Weak fuel pump
3. Relay if it is a relay, is not the problem. if it is indeed magical, it is on the table
4. Regulator if all else proves not the problem
Plan
1. Jump the relay
2. I will go get a pressure tester and appease the masses there.
3. Install filter upon receipt.
4. get a replacement pump
5. What was the voltage test, look at the voltage when decellerating essentially?
Is this approved? As I do want the guidance, but also an open discussion on the situation.
I agree about the pump. BMW standard is likely much higher than aftermarket high performance. Personally when my fuel pump goes I will spend the big bucks and get a bosch likely two from 2.5 liter engine. That said I have been driving BMWs for 20 odd years and only lost one fuel pump. I change my fuel filters every 60-80k km and I don't run to empty very often.
If I did not like you I would not have yelled.
If you are having issues with the fluctuating voltage idea then go to the WDS and look at the fuel pump wiring. I know you know where it is it was up in your screen shot. On the NA model you see the module now look at the euro model just a simple relay. The systems are identical except US law has some other requirements for fuel shut off and monitoring. So the ekp module is used as extra protection to shut the pump down. When Joe cuts his apart I am sure we will see a double relay for lack of better description. In other words two switches on the activation coil.
Fuse 54 is battery power it comes from fuse 102. That fuse feeds f51-f55 things like window motors trunk release and lighters which all get battery power. Once the relay is closed fuse 54 feeds the pump. It is all there in black and white.
For anyone else who is not proficient wds is here WDS BMW Wiring Diagram System - 5 E39 from 09/98
in the lower left search box enter fuel pump then click search. Click the + beside the highlighted title and you will get 4 headers for diagrams and one header for the overview. Read them all they all run the pump the same way and decide if the ekp module controls pump speed. If it does then it only happens on US cars.
14Likes
Linear Mode
