Eddie95Z28

When testing the knock sensor. Do I set the DVM to AC or DC ? And assuming the 5v wire is bad, which I think it is. How do I go about replacing it.

Eddie95Z28

Well as an update to my situation. I have DTC 43 Knock sensor circuit failure.

I tested the wire from the PCM to the KS and it is good.

Now here is the problem. The knock sensor itself is showing open.
but I am not sure if the if 4000Ohms is in the range of the tester.

and ALSO the PCM isn't getting a voltage. But I am not sure if I am testing that part right. I disconnected the blue PCM line and put the engine in ON but not running and counted over to pin #22 on the PCM not the narness. Stuck the +lead from the DVM on the best I could and the -lead to the - on the battery and got nothing. or .2v at best.

Where do I go next?

Injuneer

Pull the connector off the sensor. With the ignition "on" check the voltage between the single pin in the harness connector and the block. You should see +5V DC.

With the connector off, check the resistance from the single pin on the sensor to the block. Should be 4,000ohms.

Put the harness connector back on the sensor. Check voltage from single pin to block.... should read 2.5V DC.

When the KS operates, it will overlay the sound frequency signal (AC) on top of the 2.5V carrier voltage.