Code 31, Knock sensor wiring

[chucklesas]

Okay, so I think the knock sensor is pulling my timing, even at idle I show 9 counts of knock and I assume this is a safety feature when the knock signal is bad? Anyway, I pulled my harness apart, it appears someone else spliced this wire before I did (didn't peel it that far back the first time), because of this, when I put my wiring together I had reversed the ground and the signal wires (hence my code 31). I'm trying to solder in a new coax (I'm just going to use the techniques our electrical guys do on the airplanes to splice in a coax). Getting to my real question... Is the shielding supposed to be connected to the black ground wire that runs up to the knock sensor? I peeled the harness pretty far back and saw that the coax wire had been spliced to the black ground wire. If someone could call me with the answer, I'd appreciate it: two one six four zero one eight seven nine one

Thanks.

 

[Hertz]

I don't think the shielding is supposed to be connected to anything, it's just to reduce RF interference.

 

[Terry Posten]

Shielding works best when only 1 end is grounded to chassis. But you need to be sure that it is only a shield and not a ground point to whatever is driving the sensor.

 

[Muskrat]

OEM the shielded wire was a 1 conductor wire with the ground running through the shielding. The black wire was crimped to the shielding, and the shielding was crimped to a ground circuit under the dash by the ECU (grounded to chassis).

you could do this, or follow terry's advice and only ground one end, and run a separate ground to the chassis. Make sure the ground wire is also shielded. I think 2 conductor shielded wire would work fine too, but don't quote me on that I'm an ME, not an EE.