# Help. Multiple fault codes



## John222 (Oct 11, 2008)

Helping a friend, his Cabrio 2.0L is having issues with misfires and problems filling his gas tank. He said it almost seems like the filler tube is blocked. However, one of the codes indicates a problem with the vent valve. I suspect all of these codes will lead back to one or two electrical problems. Any help would be appreciated. Codes are as follows; 

16645 - fuel injector #1 short to ground 
16648 - fuel injector #2 short to ground 
16651 - fuel injector #3 short to ground 
16654 - fuel injector #4 short to ground 
17833 - tank vent valve short to ground 
17859 - secondary air injection system short to ground 
17880 - EVAP leak detection pump short to ground 
16684 - random multiple misfires 
16687 - cyl #3 misfire 
16686 - cyl #2 misfire 
16685 - cyl #1 misfire 
16839 - EVAP emission control gross leak detected. 

Could the fuel pump relay be causing some of these problems? 

Thanks


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## Anony00GT (Mar 6, 2002)

Check the fuel pump relay. If the terminals are blue from heat, replace it. New one should be OE from the dealer only.

Check LDP and vent valve for proper operation. Offhand, I don't know if they get power through the fuel pump relay or not, but I know the injectors do. Check the wiring diagrams on that one.

Do you have full VCDS, or are you extrapolating VAG codes from P codes?


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## cdncountrybuggin (Sep 16, 2012)

John222 said:


> Helping a friend, his Cabrio 2.0L is having issues with misfires and problems filling his gas tank. He said it almost seems like the filler tube is blocked. However, one of the codes indicates a problem with the vent valve. I suspect all of these codes will lead back to one or two electrical problems. Any help would be appreciated. Codes are as follows;
> 
> 16645 - fuel injector #1 short to ground
> 16648 - fuel injector #2 short to ground
> ...


That curcuit is powered by the fuel injection relay!


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## John222 (Oct 11, 2008)

Thanks guys. I called and told him to replace the fuel pump relay. 

Also told him to manually exercise the gas tank vent valve located in the filler neck for his gas filling problem.


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## John222 (Oct 11, 2008)

Problem solved, It was the fuel pump relay.


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## John222 (Oct 11, 2008)

Looks like I was premature. He's still got the same codes even after replacing the fuel pump relay. Any suggestions?


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## Anony00GT (Mar 6, 2002)

John222 said:


> Looks like I was premature. He's still got the same codes even after replacing the fuel pump relay. Any suggestions?


Did you use the latest OE relay from the dealer? Or Chinese relay from the internets?


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## John222 (Oct 11, 2008)

I think he picked it up at advance auto or autozone.


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## Anony00GT (Mar 6, 2002)

John222 said:


> I think he picked it up at advance auto or autozone.


That's the problem. Get one from the dealer and retry.


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