Those people that have had bad knock sensors: What resistance reading did you get? I measured mine, and my ohmeter showed no reading whatsoever (the ohmeter can read as high as 2000kOhm). I know that its supposed to be around 560kOhm. Did anyone else get no reading? I'm pretty sure the ohmmeter is working fine as other metal parts in the engine bay measured random resistances.

Also, does anyone on the board have a knock sensor for sale?

 

that usually means it's bad. Still, just make sure you are not taking the reading at the harness since one of the leads is open-ended. Only the signal lead goes to the KS. The KS has a metal bottom that is grounded.

 

I was measuring from the battery negative terminal to the pin that is closest to the front of the car. Does this sound right? I was not measuring the removable harness that plugs into the connector.

 

run your car for a few minutes till it warms up and then take the reading it should read anything b/n 500-600.

 

wait, does this mean you HAVE to take the reading with the car on?

 

I just did mine today. Car does not have to be on, I got 550k. I just put one end on the neg of batt and tried both of the two pins till I got a reading.

 

The harness has a clear jacketed wire which is the signal. In any case, one lead should be 550k, the other should be discontinuity. If both are discontinuity, then you know the KS is bad.

 

The car need not be running.I'm sorry i wasen't clear.Run the car turn it off and then take the reading.. it should read around 560.If you want a voltage reading from the KS then the car needs to be running and the voltage should be something around 2v.

Take care,
Jay

 

Thanks for the info, I've been searching on and off for what's been causing my engine surging since I got it about 3 months ago. I just checked my ECU and it spit out 0304, the famous knock sensor error. Just for grins, I measured the resistance at 1.2 MOhm, about double what is normal. I cleaned the ground connections and cleared the ECU code, so now I'm gonna take it out and see if 0304 comes back. Might even put a 550k resistor in the circuit and see if it really flies!

 

I doubt stuffing a resister in line is going to work. In any case, if your KS is reading 1.2MOhm, I'd just replace it and be done with it. How often are you going to want to pull codes to see if the 0304 pops up? My KS did not die all of the sudden. At times, you could clear the codes and it would not come up the next time I checked. Quite rapidly though 0304 showed up more and more and when I took it out and measure it, it initially did not put out a resistence (discontinuous) but at times would also be on the order of 1+ MOHms. Ultimately, it constantly put out 0304 no matter how many times you reset the ECU. I think it is even more troubling if your casing (the black plastic part) of the KS is split open a little as many of us have found on ours.

 

After I cleaned the manifold grounds and tightened the connections, the reading went down to 1 MOhm. 200K less than before! I took it for a spin and it's WAY better. I think I'll pull the knock sensor and see it cleaning anything in there will get it a better ground and more normal readings. Thanks for the cracked casing tip too. I'll continue to monitor any codes and further symptoms, but it looks like I finally found the culprit to the surging. And I'll probably be ordering one in the near future anyway.

 

Just an update here - my max is still running much better but I still got the knock sensor error code out of the ECU today. SO... I'll be buying one shortly. Just glad to know I found a cure.