MacEwen

I'm sorry if this was covered elsewhere. I found my searches weren't productive.

I have a no start condition. Engine cranks. I replaced tank fuel pump 5 months ago. Similar symptoms. Monday morning after a nice long weekend trip I crank and crank and no start. I applied 12V directly to pump pins, pump runs, car runs. I checked fuel pump fuse, fuse is good. I VHS k voltage at pump plug and its 0.98V across pins 1-5, or red and chassis ground.

I'm hunting for fuel pump relay. I have an 'ebay' manual which covers 2005-2007 A6. It's showing a fuel pump relay as being no. 2, in left side e-box under engine cowl. I opened it all up today to replace relay, and it doesn't appear to be the correct one. I took old relay cover off and it looks fine,and appears to be working. I must be toying with the wrong one. :/. Can anyone say for sure where it is on a 2005 A6 3.2l?

I saw video it's under dash on 2004. Hmmm.

MacEwen

Btw I ordered a Bentley CD-ROM last night. But, tracking says it won't be here until next week. Grr.

MacEwen

My CD-ROM arrived. It freezes on install onto XP laptop of mine. I've been granted access to online literature.

I have only located a 'fuel pump module' in component locations, and wiring diagrams.

I removed access panel in the trunk, and there is no module present. There is just a rubber block closing the channel under it.

I'm very stuck. I scavenged the internet for pictures, and came up with contradictory info. I guess I have an early 2005 model, which some lump into C5 or C6. Can I tell this from the VIN?

I cannot tell if I have both a relay, or one or the other (fuel pump relay, and/or fuel pump module. The fuse is good. Yet I cannot get power to the pump connector.

A6Gary

Per Bentley Repair Manual, the fuel pump control module J538 can be located in two positions. It could be located in the front passenger side luggage compartment, beneath the carpet; mounted on bottom of access cover. Alternately, it could be mounted on underside of floor access cover. If you have access to the Bentley Manual, perform a search on J538, and you'll see the page that IDs the location. The fuel pump relay for your 2005 A6 is in Position 2 (middle) in the the E-box, which is located in the left (driver's) side plenum area. Note you may also have a failed ECM, which appears to also causes the infamous P2404 EVAP DTC.

MacEwen

Gary,

Thank you so very much.

I did find the fuel pump module. I began to re-read my 'ebay cd-rom' pdf.

Being new to Audi I thought J538 was a testing tool, they were telling me to use. lol. At any rate, after re-reading it, in despiration. (and searching a bit more on the web, I found pictures of the module.) The PDF, which seems likely ALLDATA instructions on removal, points to it's location as beneath the right rear passenger seat, next to the low pressure fuel pump locking ring, UNDER the sheet metal. They go on to describe unhooking the fuel lines and pump connector, loosening some bolts supporting the tank, and tipping the tank down to get it out.

I am at a loss as to why this location wasn't mentioned in the Bentley literature. I noticed the Bentley pictures were calling out m.y. 2005, but the date was 08/05. The wiring schematic shows power coming directly from a 20A fuse. Slot 1, row 2, right side of dash fuse panel. I tested red/yel wire at module harness, and it has positive power. (If I apply positive to pin 5 on pump, pump runs, car starts no problem.)

I have the e-box cover off. There are two relays on the top, the third relay area, is empty with no contacts present. Are there more buried under there!?

I put in a test relay and closed it manually, and a slight suction, noise is created at the engine (Pfft noise, reduces in duration, the more I open/close relay), but fuel pump doesn't run. (unplugged pump, and had power probe hooked to connector. No 12V+ present when I close this relay. The relay I played with was in the middle, at the top.

The Bentley illustration, and others, show a location of a fuel pump relay, but it's not in the wiring diagram for the module. It's a tad confusing picture since there is 1.1 1.2 1 2.1 2 2.2 ... etc. Theres also a dashed line dividing each of the 3 locations. They are both 1 & 2 4-blade relays.

Very confusing. I'm leaning toward ordering the module, and slipping it in place of the old one. :/ I wish I new for certain about any fuel relay. I see they are listed at autoparts stores, and even bought one. It fits in place of the others, and has correct 2 wide blades. Doesn't appear to change anything related to fuel pump or module though. :P