Knock sensor scan! Can anyone check theirs for me?

[VENOMOUS1 RACING]

I am showing a funny looking signal from my knock sensor and was wondering if anyone withthe knowledge or scanner can let me know what their knock sensor is reading? It could be the scanner program, although it specifically covers the SRT-10? But it only shows KNOCK SENSOR 1 and no SENSOR 2? Sensor 1 jumps between .29 volts and 4.5 volts about every second and it is definitly false because it does it with KEY ON/ENGINE OFF as well. Any input would be greatly appreciated.:rock:
P.S. Although it shows this it doesn't seem to be affecting timing?:dontknow:

 

[HaroldD]

I don't have my Modis with me at work, but here's a waveform from another vehicle from the IATN...

"1996 Dodge Grand Caravan ES, KS Waveform
By: Harvey ChanBy: Harvey1/2/2005 4:51:27 PM
Capture of knock sensor while tapping on the block with a hammer."

Looks to me like it should be steady-state with a jump in voltage only in response to the input (hammer in this case).

If your's is jumping at idle per your scantool, I'd backprobe the sensor with a labscope to make sure that's what the sensor is really outputting, then either replace the sensor or check wiring to the PCM from there.

 

[VENOMOUS1 RACING]

Thanks Harold!! Do you happen to know for certain that we have 2 sensors or just 1. I just had the intake off and I'd swear that there are 2?

 

[HaroldD]

I don't know for sure one way or the other. :dontknow:

Thanks Harold!! Do you happen to know for certain that we have 2 sensors or just 1. I just had the intake off and I'd swear that there are 2?