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Discussion Starter #1 (Edited)
I need help with yet another fuel pump problem. My primary pump failed and I replaced it. The car started and ran fine a few times over a few days and then wouldn't start again. Instead of starting up instantly it cranked for two or three seconds so I suspected that the secondary pump was no longer running. By way of troubleshooting, I used an outside battery to power the secondary pump and it runs fine. I reconnected the connectors and ran power to the external connector on top of the filter housing and again the pump ran fine. By following several threads I checked all the fuses in the car and they were all good. I found the 404 relay and removed it to check power to the number four terminal and it has power to it. I swapped this number 404 relay with another one and that didn't help. When I opened the driver's door I cannot hear the pump come on. The convenience light comes on when I opened the driver's door and I hear the door chime. To me this indicates two potential problem areas: a break in the wire between the number 404 relay and the fuel pump, which I doubt, although there is no power transmitted to the connector at the fuel pump. The other possibility is that the switch or switches that activate the number 404 relay are not sending a close signal to the relay. I am to the point of running new wires from the secondary pump to a toggle switch on the dashboard. HELP! Thanks, Fred.
 

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Fred - first scan it for codes to see if anything comes up - especially in the door. I assume you have already ruled out fuses.

Does the door show as open on the dash when it is open?

The other thing you can try is to see if the relay is getting power when it ought to be.

You can test the wiring by running a continuity test on them - with the relay pulled, jumper the connector (removed from the pump) and test continuity at the relay's connection.
 

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Discussion Starter #3
Did scan and no codes but will do it again. I checked every fuse in the car. What is frustrating is the lack of continuity between the cards that are supposed to list the fuses and the actual fuses. The forum says that the pumps are run by fuses number 13, 14 and 15. I do have those three fuses but they are not labeled on the cards and in fact there is nothing associated with the fuses that even mention fuel pump. So without the forum there is no mention on the fuse cards, the fuse holders or the numerous books that come with the car there is no way to associate any fuse with fuel pump. The door does show as open on the Dashboard when it is open. The number 404 relay shows an incomplete wiring diagram. I am guessing that the primary circuit is contact number one and two with number two showing 12 V. The nonstandard diagram doesn't give a clue how power gets to the appropriate contact, whichever it may be, three, four or five. It would sure help to know which contact receives the 12 V for the secondary and which of the remaining contacts run to the fuel pump. I will do a continuity test on the line to the fuel pump connector.

On another subject, I was the victim of the syndrome wherein both cooling fans continue to run after shutting off the ignition until the battery goes dead. Per the forum, I took out what I believe to be a perfectly good and strong battery supplying 14.7 volts and replaced it with an AutoZone battery and the few times I got to run the car before the fuel pump quit, the fans worked as normal. I now am left with the only major error message being the airbag is inop. The new battery didn't solve that one. I read that this is a common fault and I should hardwire the lines that currently go through the connector. Is that the big red connector in the assembly that sits beside the battery? I considered pulling out that connector, clipping the wires and using new connectors but I thought it to be safer to pull the fuses that protect the airbags. But of course there is no indication anywhere where those fuses may be, if there are any. My question is: do I need to pull the airbag fuses, if I can find them, before I clip the wires and reconnect them and is the connector that I need to replace the big red scary looking one?

I have owned several hundred different vehicles and I place the Touareg very near the top of the best cars I have driven. But after a couple years with this creature I am becoming more and more disgusted with the details of the machine. I have worked with wiring and electrical things all my life including vehicles and aircraft, private and military and I know my way around fairly well. But when a manufacturer can't even label the fuses on their power boards I consider that to be totally disgusting. After reading some of the horror stories other people have encountered I'm afraid to keep the darn car. I just traded in my VW Passat and I'm starting to cast a wary eye on the Touareg. When it all works, it's an exceptionally great car. When something doesn't work, even the dealer is stumped. I recently made a list of fairly easy items that needed to be attended to and took it to the nearest big VW dealer which came highly recommended to me. After three days they did nothing more than clear codes and sent me on my way. So I fixed most of the items myself but cannot get rid of the airbag fault. They said they checked the connector under the seat and everything was fine and after that they cleared the codes. I didn't even make it home before the airbag fault light came back on. They said there were 642 sensors in this car. I believe the task is like keeping 642 wives happy all the time; never gonna happen. If I could find 640 of them I would snip them out. The happiest day of my recent life was when I figured out how to turn off the flat tire indicator. The only time that I wasn't getting a low tire indication was when I was 45 miles out in the boonies and my tire actually went flat. The low tire indicator didn't say a word.

Thanks for the help and I will finish the continuity check. If you know which contact in the relay is supposed to send power to the pump, that would allow me to check out that part of the equation. I suspect that's where the trouble lies.
 

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Unfortunately I can't help with the location of the items you are asking about. I would suggest that you put your airbag fault question in its own thread.

The only useful information I can give you on the airbag wiring is that you ought to not bother just removing fuses when coming into close quarters with anything in the airbag system, you should be disconnecting the battery.

Good luck.
 

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Fans running is possibly a symptom of a bad temperature sensor on the cylinder head. Replace them and the o rings. Or possibly a bad temp sensor on the radiator.
 

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" is the connector that I need to replace the big red scary looking one?"


NO.

The common fault that causes the airbag light to come on is the loom stretching at the YELLOW connector under each of the front seats as the seats sag with age, or if some very fat lard-arse sits on it!

But, first, have you tried to reset the airbag fault code [and therefore the light] with VCDS/VAGcom or a good code reader with reset capability?

If you haven't, then THAT is the very first thing to do since even if you hard wire the yellow connector, you will still need VCDS/VAGcom or similar to do the reset and clear the light - it doesn't just reset itself.
 

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Discussion Starter #7
Back again after only six months or so. I have let the car sit because I was ready to kill it. noobytoogy, I love that "no".
Fuel pump continued: I read in the forum that replacing the filter should turn on the fuel pumps. Okay so I ordered one and it came today.I don't know why I expected the new one to look like the old one and of course it doesn't. The old one has two hoses coming out of the top and the new one has only one. The all-in-one has two hoses coming out of something on the bottom that looks like a rotary pump. The new one has a hose already attached and two more nipples that are capped off; one Is probably temporary. The old one has absolutely nothing pertaining to a filter; just that rotary pump looking thing. The new one looks to be a filter. There is no possible way to connect the hoses coming from my unit to the new unit because there are too many outside the tank and the ones inside are vastly different sizes. I would love to see a plumbing diagram for the entire fuel system because I would probably re-plum the entire car, which I'm quickly starting to hate. Does anybody have any constructive ideas? When members of this forum talk about the fuel filter and I receive what appears to be a fuel filter in a box, this I can understand. But where everybody else seems to have a fuel filter installed, I have a plastic carry through for the wiring and fuel lines which has an unknown rotary something attached to the bottom of it… And no filter. I'm sure there's a filter somewhere, but I haven't found it yet. HELP and thanks.
 

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lol thats because your in the wrong hole fool!! sorry icouldnt help my self... for any one reading this later. the fuel filter is on the left side of the t reg. the other unit pictured above is a sending unit for the fuel system. any how that unit is on the right side.
 

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Discussion Starter #9
It's a long story how I got in the wrong hole in the first place. I replaced both fuel pumps and had the fuel filter out at one point. Neither pump would run so I closed up the filter hole and went looking for an electrical reason. I did all of the electrical checking to no avail so I simply parked the beast for several months. I also had a bazillion warning lights on but replacing the battery got rid of all of them, except the airbag light. After reading in the forum that the fuel filter could turn off the pumps, I bought the filter. When I opened up the beast after many months, I think about a year, there was this still open hole waiting for me to jump into. Of course it was the wrong hole because I had already closed up the one with the filter. If that other gadget is a sending unit, it must be for the quantity?
 

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You'll need to clear the airbag light with VCDS. Note that while the light is on the airbag does[do] not deploy.
 

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Any body know why the both pumps work when 404 fuel pump relay is pulled out? And when plugged in the car shuts off after 30 sec. Any input
 

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lol thats because your in the wrong hole fool!! sorry icouldnt help my self... for any one reading this later. the fuel filter is on the left side of the t reg. the other unit pictured above is a sending unit for the fuel system. any how that unit is on the right side.
Are you sure that the picture is the sending unit? If you go online and search sending unit for the touareg it is completely different in appearance and is in the fuel tank. Only place I found what is pictured is on ecs tuning. They call it a fuel filter for the secondary? Understand the filter sits in the dome of the filter assembly on the primary side. The secondary is to small for a filter, but has a removal element ( copper) I thought was some kind mini pump. Maybe there is a small filter inside? Anyway have seen plenty of discussions concerning fuel pumps and primary filter, but nothing on this component. It would seem a failure in this unit would cause a no start issue even if secondary pump worked?
 

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Are you sure that the picture is the sending unit? If you go online and search sending unit for the touareg it is completely different in appearance and is in the fuel tank. Only place I found what is pictured is on ecs tuning. They call it a fuel filter for the secondary? Understand the filter sits in the dome of the filter assembly on the primary side. The secondary is to small for a filter, but has a removal element ( copper) I thought was some kind mini pump. Maybe there is a small filter inside? Anyway have seen plenty of discussions concerning fuel pumps and primary filter, but nothing on this component. It would seem a failure in this unit would cause a no start issue even if secondary pump worked?
Your right that is a regulator the sending jets are at the bottom of the tank
 

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Interesting that VW calls both the fuel filter and pressure regulator assembly flanges. Hard to believe the
That the pressure regular assembly costs almost twice as much as fuel filter. Wonder how long the pressure regulator lasts. Don't see many posts about replacing. Would seem that it would wear out over time.
 

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That the pressure regular assembly costs almost twice as much as fuel filter. Wonder how long the pressure regulator lasts. Don't see many posts about replacing. Would seem that it would wear out over time.
Are you talking about the price of just the filter? Because I paid 167 for the flange with new filter.
 

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where did you buy your assembly from? and are these all the fuses and relays related to the fuel system?
Partsgeeks.com as yes those are all the fuses and relays for the fuel pumps. But I only pulled the first relay out and my car runs. And still runs. When I put the relay back in the t reg turns off after 30 seconds of starting it. So I am assuming the pass. side pump is out. I thought the driver side was the problem and I regrettably replace [email protected]$267 and it did not solve my problem. I replaced the fuel filter flange assembly and still nothing. So for all future t reg owners with this problem remember in the V8 4.2L the driver side pump primes and starts t reg. pass. Side pump runs the pump during the ride.
 

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Partsgeeks.com as yes those are all the fuses and relays for the fuel pumps. But I only pulled the first relay out and my car runs. And still runs. When I put the relay back in the t reg turns off after 30 seconds of starting it. So I am assuming the pass. side pump is out. I thought the driver side was the problem and I regrettably replace [email protected]$267 and it did not solve my problem. I replaced the fuel filter flange assembly and still nothing. So for all future t reg owners with this problem remember in the V8 4.2L the driver side pump primes and starts t reg. pass. Side pump runs the pump during the ride.
The relays in the ebox vary based on engine. The v6 has c19 404 by the small fuses and a6 last row of relays top relay in the ebox. One of the vw study manuals indicates relay J 17 pump primes the car at start up however same manual indicates C19 & A6 as fuel relays and there is no J17'? Ebox diagram shows C19 in the wrong space. The board is marked and what is labelled C19 in the book is actually C20f. Iam completely confused about what pump is primary and what pump is secondary. There are conflicts within the forum. When I open the door the pump sound seems to come from behind the driver seat not the passenger side which I thought was the secondary.

When the car is running you can pull C19 and nothing happens. Pull A6 and the car shuts down. WTF does anyone know what relay drives what pump and which pump is primary and secondary on a V6. Are the V6 and V8 the same? I find no definitive answer in this forum or on fuel pump threads back to 2009. Someone must have cracked the nut besides just replacing both pumps. I am so fed up right now I am going to replace both pumps when I know for a fact that only one pump is bad. Problem which one?
 
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Elysium Lee Carey
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