P0688 code ecu relay

[Black_Pearl_B6]

Picked up a car cheap as a donor, the guy said it ran but needs a starter solenoid now, so I got it home scanned it and got that code. Vag com says that the ecu relay is an open circuit or the relay isn’t there.

So I was wondering where is that relay and how could I jump it.


I wanted to at least hear it run before I part it out


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[VinnysS4]

2 places to check:
Under the drivers dash and in the ecu box under the Ecu


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[Black_Pearl_B6]

2 places to check:
Under the drivers dash and in the ecu box under the Ecu


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Yes I found all of those relays, just not sure which one is for the ecu it also looks like some water got under the ecu hmmmmm


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[q_dubz]

looks like you found your issue. common. now stop thinking the answer is a part out.

[VinnysS4]

There’s your problem. The “main” relay I believe is the one In your hand. Either way, you Need to clean the relay sockets and probably replace the relays. Then you need to replace the ECU seal on the box or this will happen again. Once you get this taken care of, you should be good to go.


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[Black_Pearl_B6]

looks like you found your issue. common. now stop thinking the answer is a part out.

Well I just bought the car for $1000 to part it out and fund my other build but when I started asking a few questions when I put it on the trailer I could tell he had no idea what he was talking about so I figured I’d try to get it running it’s got 222k


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[Black_Pearl_B6]

There’s your problem. The “main” relay I believe is the one In your hand. Either way, you Need to clean the relay sockets and probably replace the relays. Then you need to replace the ECU seal on the box or this will happen again. Once you get this taken care of, you should be good to go.


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Anyone know what terminals to jump to verify that’s the issue? I made a jumper and tried jumping the two larger connections, and no dice. Like so...


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[VinnysS4]

Relays use terminal 30 for power in and 87/87a for power out(depending on NO and NC circuits)


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[Black_Pearl_B6]

Update: I jumped that relay that I was holding in my hand in the photo and the SAI pump powered on and I had no luck so I jumped a couple others and had no luck, I tried all the relays in the driver knee bolster and had no luck it looks like none of those are actually for the ecu or that is not the issue


It appears by the codes that the ecu is not getting power. Does anyone have access to bentley or Chilton a where I can find the relay that’s for the ecu cause I don’t think those are, or where I can find a wiring diagram to find which wires power the ecu