Knock sensor still unsolved mystery
Posted: September 28th, 2007, 2:05 am
I know many have bin in this situation, but I can't find (on any forum) a clear answer to what is needed to be done with this.
From my KLDE I have one connector (diamond shaped) with one wire and from my k8 I have another connector (square shaped) with two wires.
I know the knock sensor is just a microphone that needs a stable voltage (2,5v I've heard) and it makes diffrent resistance accuring to the sound of the engine witch then again makes a vibrant voltage for the ecu to manage.
To make this happend we need a voltage supply from the ecu (could bin earthed in the ecu and the voltage from another location, but I don't think this is the case) and the sensor earthed some how.
I think that the main difference between these sensors is that the one with one wire, the casing on the sensor is earthed. The sensor with two wires gets earthed another place.
I could be on deep water if that sensor got its earth from the ecu, because it would then probably be listening on the earth instead of the +voltage. But I managed to measure that one of the wires is earthed on to the engine manifold (even when the ecu and all the ground wires where removed, a lucky shot).
As to this I belive I can just switch the connector over and connect the one wire in too the right spot on to the two-wire-connector, not doing anything with the earth.
As a more safe way to go the wire up to the diamond shaped connector has an outer shield that is connected to earth. I could put this in as an earth to the two-wire-connector as well..
Can anyone confirm my theories and assumtions?
I know I could just change the whole sensor, but it would make a lot more work for me.
I know it was a lot to read
From my KLDE I have one connector (diamond shaped) with one wire and from my k8 I have another connector (square shaped) with two wires.
I know the knock sensor is just a microphone that needs a stable voltage (2,5v I've heard) and it makes diffrent resistance accuring to the sound of the engine witch then again makes a vibrant voltage for the ecu to manage.
To make this happend we need a voltage supply from the ecu (could bin earthed in the ecu and the voltage from another location, but I don't think this is the case) and the sensor earthed some how.
I think that the main difference between these sensors is that the one with one wire, the casing on the sensor is earthed. The sensor with two wires gets earthed another place.
I could be on deep water if that sensor got its earth from the ecu, because it would then probably be listening on the earth instead of the +voltage. But I managed to measure that one of the wires is earthed on to the engine manifold (even when the ecu and all the ground wires where removed, a lucky shot).
As to this I belive I can just switch the connector over and connect the one wire in too the right spot on to the two-wire-connector, not doing anything with the earth.
As a more safe way to go the wire up to the diamond shaped connector has an outer shield that is connected to earth. I could put this in as an earth to the two-wire-connector as well..
Can anyone confirm my theories and assumtions?
I know I could just change the whole sensor, but it would make a lot more work for me.
I know it was a lot to read