Just aquired a 99 Legacy, my first Subaru while looking under the dash for the fuse panel I noticed a single wire above the gas pedal that has a green plug on both ends. This wire is unplugged , seperating the wire. I conected the plug and started the car, the check engine light flashed continuously. So I unplugged the wire. My Q is, should this wire be left un plugged or is it normally conected?

That wire has something to do with the diagnosic mode for the engine computer. It's supposed to be disconnected. Why it hangs down like that is beyond me. I'd tape/ziptie it up out of the way.

Alot of cars with puter have this. It bypasses something in the puter so the mechnaic can help to troubleshoot, but for the life of me i cant remember what it does.

Not all wires under the dash are meant to be pluged in

 

 

nipper

Yes, you need to leave that disconnected for normal driving, it is only connected when doing certain diagnostics. Legacy 777 has written a lot about it.

 

 

matt

Ahh yes... The good old diagnostic connector. Just leave it unplugged. I think ALL diligent folks here with later models have stumbled across this.

Hey, thanks all for replying.