Fuse E6 Blown/ Short, Issue Filling Up

[dbeasty]

I have the E6 fuse blow, which I think is the cause for fuel vent valve not engaging and hence having issues filling up.

 

I have detected short ( there is 12 V across the fuse ) and keeps blowing.

 

Where would be a good places to look for the short?

Or suggestion how to narrow this down.

 

I did open the wheel well and looked at the fuel vent valve, and the wires seem to be ok there.

 

My radio seems to be working with an aux input, but that might not be an indication of anything; also the Boxster is in the garage so should not be damped but..

 

 

 

 

[JFP in PA]

Welcome to RennTech 

 

You need to do some electrical diagnostics here; I would start by pulling the vent valve and checking it both electrically and for function.  The valve itself can jam, causing the short.  If the valve checks out, you need to start testing and possibly tracing the wire going to the valve; one or both may be shorted.

[dbeasty]

Thanks, seems like after I pulled out the vent valve the short went away, so that is where the issue is or in connectors leading to it..

 

How do I bench test the vent valve?

 

I do not see any obvious electrical leads to it.

[JFP in PA]

This is how the tank vent is supposed to work:
The gas nozzle goes in, hits flapper, the flapper opens the magnetic "reed" switch:

 

 

that is mounted to the outside of the filler tube, the reed switch tells two electric valves to open; if you push on the flapper with something, you should hear an audible click if it is working. One valve is on the tank (under battery to the right) and the other is in a box in the front right tire well (between tire and bumper). This whole process opens venting to allow the tank to fill.

 

 

[dbeasty]

Thanks for explaining the how the entire system works.

( I will make sure to add the reed switch back where it supposed to go..)

 

I would like to bench test the tank bleeder valve from the filler neck that I took out and posted picture for.

You mentioned its an electric valve, so I would expect way to power it.

 

Are the leg screws way to power it?

 

 

[JFP in PA]

The electric valves are not in that device, that device is the vacuum connection to the fuel tank and one way check valve for the EVAP system carbon canister.  The electric valves are at #1 and #6 in this diagram (#1 is under the intake manifold, 6 is at the EVAP canister).

[JFP in PA]

I also want to ask you what will seem like a strange question:  Have you had any water intrusion in the cabin, like under the seats?  Reason I ask is that E6 shares duty with the ultra-rare factory cell phone set up and all cars are wired for it, having an unused plug for the system under one seat where the cell transmitter would have lived; if that plug gets wet, E6 blows, and you cannot fill the gas tank.

 

Just a thought.........

[dbeasty]

Thanks for explaining.

 

After I disconnected the workaround Porsche mechanic put in place for reed switch ( the reed switch was not available at the time) and after I pulled out the fuel vent valve  ( which had one wire wired to ground) the short is not happening any more.

 

I think that would eliminate the under seat short issue ( also the car is in garage most of the time and was not much in rain ).

 

I will follow up with eliminating issues, the reed switch workaround might be a candidate, after that I will try to locate the electric switches #6 on the evap canister and than the #1  which should be to the right of the battery.

[dbeasty]

I think I am pulling wrong components out :).

I took out the charcoal canister and above it is a lock to the fuel door...

 

But upfront there next to lights there is a dual valve component with electric connections so that might be a suspect.

I think the other electrically operated valve that can get stuck is in the engine compartment.

[dbeasty]

Still troubleshooting this issue...

 

Is there an electrical valve in the engine compartment that can blow the E6 fuse?

 

How does it looks like and or its position and or part number for it?

 

 

[JFP in PA]

E6 fuse is for Term.30 Telephone/Handy, Navigation Control Unit, ORVR (1999-2004). ORVR stands for onboard refueling vapor recovery system, which is part of the EVAP system, which has multiple electric valves in it: