2013 Jetta TDI sedan dsg. No access to vag com, limited access to obd11. Am I correct in assuming that when I turn the key on without cranking, and have the fuel supply line off the filter, that fuel should come out? Brand new in tank fuel pump. What could be the causes, and how would I test these other reasons why fuel isn't getting to the filter?
Mk6 Jetta: No fuel getting to filter
- Thread starter hoonhead
- Start date
I believe you should have fuel coming out with the key on, but for sure when you turn the key on, you should hear that pump in your tank it should go on for a little bit
Have you checked any fuses/relays?
You definitely should scan with your odb11
Bob S.
Top Post Dawg
Check your fuses on the dash end fuse block with a 12vdc test light. I have experienced a faulty fuse on this same circuit, that appeared on, but was not. No dtc code triggered by pump not working.
turbodieseldyke
Top Post Dawg
Why not check for voltage at the pump first? Your brand new pump might have failed.
I’m very much a beginner when it comes to electrical stuff, but I bought a multimeter and tested the plug for the fuel pump, I would see 12 volts but within 2-3 seconds it dropped to 3 volts and held around there.
The fuel pump fuse looks fine, swapped it with another 15amp fuse, also swapped what I believe to be the fuel pump relay with the only other one that would fit it, right next to it. Still no pump noise
turbodieseldyke
Top Post Dawg
The pump only runs very briefly when you turn the key On. It runs full-time while the engine is running (maybe while cranking too).
Your next step should be hotwiring 12v to the pump. Make sure polarity is correct, and don't apply voltage to the smaller fuel-level wires. But you should only do that if you're comfortable with your skills. If 12v makes it run, then your pump should be good. If not, then it's bad.
I’m game to Hotwire the fuel pump. Run me through how you would setup your test, I was going to try with a power tool battery but mine are 20v would that be too much for the pump?
Tuheeden
Veteran Member
Keep in mind that besides the tank pump, there is an intermediate fuel pump as well. Might want to check that too.
turbodieseldyke
Top Post Dawg
What i've done is take a spare car battery & use 2 pieces of wire to connect the pump terminals to the battery. I used it for several minutes to drain a tank, so i crimped some connectors on one end, and used big clamps to attach to the battery. But in your case, you're only testing it for a few seconds, so you can probably clamp the battery side & temporarily touch the wires to the pump inputs.
Bob S.
Top Post Dawg
I was unable to find a definitive fuse diagram. ALWAYS take photos of mkV and later fuse panels prior to doing any work. Use 12 test light and look for corrosion, or a high Resistance damage
Good luck with it.
Hardwire successfully activated fuel pump loud and clear,
I tried swapping what I believe to be the fuel pump fuse (f47, 15amp) on my car with another 15amp (f34 if I remember correctly) both looked fine. Also swapped what I believe to be the fuel pump relay (r3)with its direct neighbor relay (646 Audi) which is the only other of the same size. Still no fuel pump noise/prime with key cycle. If anyone can confirm which fuse and relay are fuel pump related I would appreciate.
Tuheeden
Veteran Member
Well the input fuel line to the auxiliary pump SHOULD have fuel flow when you manually activate the tank pump. If not, the the line is clogged or the tank pump is malfunctioning.
Possible in-tank fuel pump bad
Also when you do obd11 prime function or with putting key in on position check if you have voltage at the in-tank pump but only should be for a little bit
Last edited:
wonneber
Top Post Dawg
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- 2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
I wouldn't use a 20 volt source in a 12 volt system.
the fuel pump wouldn't last long.
