I replaced both sensors about 4 months ago. have had several knock sensor codes this past week, all showing bank 2 low input. I also replaced the connector, from Napa, for the rear sensor when I replaced both sensors. I am wondering if I have a bad sensor or connection, or if there is a problem in the wiring. Is there a way to test the sensor and the harness? I still plan on replacing the sensors again, and the harness(GM this time) Just want to know if there is a good test for the knock sensor and harness. Basically before and after, to see if there is a difference.


Thanks

 

1. Disconnect the appropriate sensor harness and check resistance, should be 93-107K ohms. No, Take off the manifold and test for an open or short to ground in the signal circuit between the knock sensor (KS) jumper harness connector, on the left side of the intake and KS connector. If the ohms are OK,
2. Connect your digital multi meter (DMM) between the appropriate KS signal circuit on the sensor side and the engine block. Set the DMM to AC voltage and tap on the engine block near the sensor. No signal, replace the sensor. Signal present,
3. Disconnect the PCM connector C1. Test the KS signal circuit between the C1 connector and the KS connector for an open, a short to voltage, or a short to ground. Didn't find a problem?
4. Inspect and repair the C1 KS circuit connection at the PCM. Still didn't fix it?
5. Replace the PCM.

You're welcome.

 

Guarantee you the wire for the KS is broke inside of the insulation in the drip loop section of the harness between the drivers side valve cover and the fuse box.

 

rear sensor was bad. only 4 months old..... thanks for the info on testing everything. made it a breeze to check.