S4 Shadow

The disintegration of the male knock sensor connector seems to be a fairly common problem. You can add my '87 S4 to the group. The wires (yellow, black, and twisted bare wire) are still well connected to the male "spades" which insert into the female connector. I've obtained a replacement "3WayBoschCon-M" male connector and it is embossed with numbers 1, 2, and 3 where the wires insert into the connector. From various pictures on line of failed connectors, I'm pretty sure the yellow wire goes in the middle (number 2). Can anyone who has had and corrected this problem advise as to the correct relative orientation of the black and twisted bare wire to the male connector numbers 1 or 3? If you used a different replacement male connector, maybe you can describe where the other two wires plug into the female connector?

Thanks for any help.

Mrmerlin

buy 2 new knock sensors and install them
I dont recommend that you try to fix a crumbled knock sensor connector

S4 Shadow

Two new knock sensors may be in the future, but for now the wires and male connector spades from the front knock sensor are in good shape and should be well protected by the new male connector from Roger. I just need to make sure I align the male spades with the correct corresponding female spade connectors in the already existing wiring harness female portion of the connector which is also in good condition.

So, the question remains, which numbers (1,2, or 3) on the new male connector wire inlets get which wires (Yellow, Black, and twisted bare) from the front knock sensor or is there another way to determine their correct orientation in relation to the wiring harness female connector?

Surely someone has successfully re-connected the wires that survived a crumbled male "rubber" connector to the existing female connector in the wiring harness. How did you match them up?

Thanks

Mrmerlin

In addition to my suggestion in post 2,
I also recommend that you replace the crank position sensor and the hall sensor.
Its a safe bet that these connectors are all in the same condition.

Since your machine is talking to you and its telling you that its ready for an intake refresh,
you should park the car and fix it properly so you can use it without adding band aids to the ignition system.

NOTE the chances are very good that the insulation on the knock sensors is also shedding and has lost its ability to prevent moisture from entering the wire,
this will change the signal to the computer and could possibly damage your computers .
NOTE if the LH has not been rebuilt then you will also have to rebuild it as well as the MAF.

Bulvot

Sounds like the quote from Aliens: "Nuke 'em from orbit. It's the only way to be sure."

I would be interested in knowing the pin out of that connection. The WSM shows the EZK side and shows two of the wires being connected to each other. Most knock sensors on other vehicles also have three wires, but they aren't all always used. Some vehicles provide a small voltage to the knock sensor to reduce the risk of false positives from ground loop noise, some don't. Does the 928 provide that voltage? Why do they connect two wires on the EZK side as opposed to just leaving a pin unused? Is the bare wire on the knock sensor side just a ground?

It's easy to recommend a shotgun approach of replacing everything related to a damaged part, but it's more interesting to understand the system better. It helps better manage, troubleshoot, modify and repair it in the future. And, sharing information is a primary benefit of a technical forum.