No power to Fuel Pump Controller on 2009 1.4 TSI

I had a recent kangaroo petrol problem, which degenerated into a complete stall, unrecovered, requiring a recovery to home. I'd previously had a FPC fail before and suspected the same again. To be safe, I jumped power to the fuel pump, and heard the motor work, so assumed that was ok, and ordered a new FPC

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I fitted the replacement today and checked for a voltage drop at the accessory socket, when the ignition is switched on, which usually starts some FP motor noise. I didn't get either, but decided to start it and it started ok.

 

I let it running to warm up, but when I returned after a few minutes the engine had died. I assumed the engine had started on the fuel fed when I'd temporarily jumped power to the pump.

 

I decided to check for power to the FPC and got no reading when it's disconnected, but don't know if this system always has power in, or whether the ECU can cut that power, if it senses the FPC is disconnected.

 

The FPC has 8 pins in, 2 power and 6 others. It has 5 out to the pump, 2 power and I assume the other 3 are for the fuel gauge sensor.

If the ECU doesn't cut power to the FPC when disconnected, then the problem is further forward. I checked the fuses and couldn't find any blown so far, although I'll check again. I haven't checked the ECU relay yet, as I assumed the fact it started and ran meant it was ok.

 

I had a look for circuit diagrams, but the one I found for 2009 was showing an FPR rather than a FPC, so I don't know what the 6 pins do exactly, although 3 of them are likely pass-through of the FG sensor.

 

Before I start looking for dodgy wiring or connectors, if anyone has any ideas, or info re this particular ECU>ECU relay and FPC interconnection, or any similar fails with this combination, and possible solutions.

Sorry, I can't help as you knowledge is greater than mine.

 

Just asking, would it be possible if you could answer @ggpowell2 question?

 

2011 Skoda Octavia Scout 1.8 TSI - Where is the fuel pump relay?

https://www.briskoda.net/forums/topic/526725-2011-skoda-octavia-scout-18-tsi-where-is-the-fuel-pump-relay/#replyForm

 

I suspect they also have a fuel pump controller and if you could explain where the FPC is and how to identify it would be good.

 

Thank you.

 

Kev.

I had a look at my car today to see if it had a FPC, it does.

 

Yes there does appear to be permanent power to the FPC with the engine off and key out of the ignition.

 

So I expect the fault to be further forward on the power cable.

 

Sorry, I forgot to note the colour of the power cable.

I managed to trace it back to a mis-inserted fuse. When I originally checked the fuse it was out in the wild, with rain wind, and fuse box being on the offside, meant I was in danger from oncoming traffic and rain getting on the electrics, so I took the fuse out and checked it inside the car then got out to put it back in the fuse box. I thought I'd put in the right place, but as a double check I used a count-back from the populated end of the fuses, shown on the card clipped to the fuse box cover panel.

 

When I decided to check the circuitry back to the ECU, I figured the fuse box was an easy point to eliminate. And when I removed the cover I had a JDLR moment (just doesn't look right), so I did the count back again but this time spotted and empty fuse space right in the hinge corner where it's difficult to see. Also the row of fuses above doesn't line up to the card diagram. So my original positioning with a single space form the next fuse was correct. As soon as I turned the ignition key, I could hear the pump run, and saw the voltage drop on the accessory socket, so I didn't bother firing it up, until I had enough time to run it up to working temperature, and make sure there were no more surprises.

 

I've now marked on the card where the fuses are actually present. I've also made a blow-up and mirror image of the fuse box, from the tiny handbook pic, which is only 36mm high, too tiny to see clearly, and a mirror image of reality. Essentially the manual pic and card, are just the RH drive car images, just chucked in regardless. Wonder if the LH drive Audi owners manual is similarly slipshod (if they do a model with that fuse box position)?

 

I recommend owners with this fuse box to mark the card *as populated* and take a pic of the box vs the roadside alternative faff.

 

1) card as suppled. 2) card now marked where populated. 3 actual fuse box.

 

 

 

 

 

Edited 4 October, 20241 yr by icarusi@hotmail

The fuse card is "a known thing". Welcome to the club.😊

 

I made up a PDF with all the fuse details and which fuse slots are populated so I know for the future.

 

Good luck and glad it's fixed now.