I've done a search on the Knock Sensor and there is a lot about replacing it and by-passing it. Is there a test to see if it is within spec? I'd like to test it before replacing it...

 

Pull the harness plug off, and check for +5V available from the PCM. Check from the single wire to the block. That tells you if the PCM is supplying the correct voltage, and if the wire is healthy.

What year is your car? (You need to include basic info like the year of your car in your "signature".... otherwise it makes it difficult for people to answer correctly). If you have a 93-95, check the sensor with an ohm meter... it should read about 4,000ohms +/-10%. Then put the connector back on the sensor, and the voltage measured from the singe wire to the block should be 2.5V. If you have a 96/97 the sensor resistance should be 100Kohms, and I don't know what the voltage would be with the harness connected.

If you have a scanner, when you get everything back together, hit the motor mount near the sensor with a hammer, and see if you get any knock retard.... .

 

Thanks... I'll include my sig. It is a 1995 Z28.

I assume I will be doing this test with the Key On Engine Off... right? (To test for the 5V reference)

When checking for the 4K Ohms +/- 10%, the connector is off of the KS and I'm checking from the connector with an Ohm Meter to the block/ground... right?

Last, this is where I'm confused, if I connect the wire back onto the connector... how do I test for voltage? If I disconnect the wire from the harness, the circuit would be broken and no voltage would be read. How do I make the connection to test for the 2.5V?

Thanks for your help... I don't mean to be much trouble.

 

Yes.

Yes... check from the connector tab on the sensor to the block

A small pin into the wire for one lead, attach the other lead to the block. I usually try to put a pin into the hole on the connector where the insulated wire goes in so I don't damage the wire.

 

Thanks!!!!