I remember comming accross certin numbers that would tell you if ur knock sensor is good. I cant remember the numbers nor the site or where u check it at.. if anyone has any idea what i am talking about let me know. thanks

 

550 Kohms, measured from the KS pin to ground. Although there are two pins in the harness connector, only one will show the correct resistance if the KS is good. The other pin goes to the harness shield.

 

my broken old one and new good one never showed correct voltage. Just a heads up.
Jae

 

oh yeah, correct voltage depends on the maker of the KS. There are 2 manufactures out there. pm me if u need more info.
Jae

 

what are the 2 diff voltages?

 

Do i check the voltage with the car on? what do i connect to?

 

How are you measuring voltage? A knock sensor is a piezoelectric device, and will create a very transient voltage when it senses knock. It is not energized by the car's electrical system. The output amplitude depends on the severity of the knock. You would have to use an oscilloscope to capture the output.

 

i will measure the voltage with a volt meter..

 

And you will get zero volts.

 

Nevermind - I'm a dumba**

 

Stephen, njmodi: are you saying the FSM is incorrect? It says if you measure ECU terminal 64 (white colored wire) and ground, it should read 2.0-3.0 volts when the engine is idling. If the ECU does not read volts, what does it read?

I made a mistake saying there's 2 readings for 2 ks manufacturers. There should only be 1 reading, regardless of which KS manufacturer you have.

Just to confirm the code you're getting Zipp028 do the following:
1) start engine and run at least 5 seconds at idle speed
2) turn ignition switch Off, wait at least 5 sec, and then turn ON
3) Check ecu for code (diagnostic test mode II)

The flow chart for KS goes like this
A) 1) turn the ignition to Off
2) Disconnect the ECM harness and knock sensor sub-harness
3) Check continuity between KS harness terminal 1 (left terminal if you're looking at the harness) and ECM terminal 64. It should be continuous. If not, check for shorts

B) 1) Check resistance between KS harness terminal 1 and engine ground. It should read 500-620 kohms. If ok, check harness for short. Otherwise, check the KS

C) 1) Check resistance between KS terminal 2 (left terminal if looking at the KS) and ground. It should be 500-620 kohms.

Jae

 

I got it - I was a little as to how voltage was being measured with the KS disconnected... thanks!

 

I didn't think we were talking about measuring volts at the ecu, but if that's what the FSM says then I stand corrected.

 

The FSM could be wrong (this wouldn't be the 1st time). I'm curious from a learning standpoint and future reference, how do u check the condition of a KS?
Jae

 

B and C in your post above is the way most people do it. However, I had a KS that would show the correct resistance sometimes, and then would show open circuit at other times. Evidently there was an internal connection that was intermittently flaky. After I replaced the KS it stopped giving the 0304 code and performance improved, so it was definitely a bad KS.