Knock sensor wiring

[Joshlc1988]

Hey guys, I'm having a hard time finding the g61 knock sensor wiring information on a 06 a4 2.0t . I've had small timing issues and poor power delivery for a long time now. After getting the fuel system right I finally found that the front knock sensor g61 has a wire that's broken right at the connector. There are 3 wires, a red/white/ and black wire. The black one is broken. However the car has no codes for it and the knock sensor test always comes back system ok. But block 26 voltage is different for each cylinder.

I'm trying to figure out the role of each wire on that sensor. Is one a voltage,then shield, then ground? Or are two signal voltage and the black ground? I'm asking because I'll have to take the make connector apart and repin the black wire or solder it back together.

While logging block 20, cyl2 will show values up to -10, and the others only show -3 to -4. I'm guessing the negative values are timing pull? Even under light throttle cruising I will get negative values, but none at idle. If the - values are not pull someone please tell me.

[blakefife]

Hey guys, I'm having a hard time finding the g61 knock sensor wiring information on a 06 a4 2.0t . I've had small timing issues and poor power delivery for a long time now. After getting the fuel system right I finally found that the front knock sensor g61 has a wire that's broken right at the connector. There are 3 wires, a red/white/ and black wire. The black one is broken. However the car has no codes for it and the knock sensor test always comes back system ok. But block 26 voltage is different for each cylinder.

I'm trying to figure out the role of each wire on that sensor. Is one a voltage,then shield, then ground? Or are two signal voltage and the black ground? I'm asking because I'll have to take the make connector apart and repin the black wire or solder it back together.

While logging block 20, cyl2 will show values up to -10, and the others only show -3 to -4. I'm guessing the negative values are timing pull? Even under light throttle cruising I will get negative values, but none at idle. If the - values are not pull someone please tell me.

i just got done doing a headgasket on my 2006 a4 2.0t quattro the other day. i accidentally broke my alternator connector, but i thought it was the knock sensor connector because i wasnt finished re-installing.

when i got down to the last two plugs, i figured out it was the alternator plug that was actually broke. but I can confirm what youre describing on your car, my car has as well. A black wire that is snipped right at the insulating jacket at the plug for the knock sensor. my guess is it was cheaper for audi to just include that wire in the harness and have someone on the line snip it. not sure though.

I did note this. but also i found out this is normal because the plug is two prong. as long as you have the two wires on there, youre good.

if your voltage is different for each cylinder, maybe this could be ignition coils, ignition wiring issues, spark plugs incorrectly gapped, wrong spark plugs. i would look along the lines of the ignition/spark system of the car.

hope this helps.

[Joshlc1988]

I took my intake manifold off today and started a tear down to fix the front cam seal. I noticed both knock sensors had this wire. I talked with dru from JHM today about it an he seemed to think the same as you. I did notice a LOT of carbon buildup on my valves again! So I'm hoping that's what's causing the pull. I also rechecked my timing on the front before I pulled the sprocket an all is well. I just did a carbon clean in December maybe 5'000 miles ago, but my valve cover failed so maybe that's why. Coils and plugs are new. I did trace these 2 wires all the way back to the ecu and they are pinned to it, but maybe have no function? It appears they are grounds. Thanks for letting me know tho I'm not the only one. I'll keep this updated

[klrider44]

I remember replacing my knock sensors and thought the same thing about that one wire. It did concern me when I first saw it but then realized that it was just like that


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