Hello,
I like many other have replaced the knock sensors in my '94 850 Turbo wagon. And shortly thereafter the check engine light illuminated and the fault code showed the rear knock sensor. A local Volvo dealer checked my work and tested the sensors and said I did everything correctly, and the sensors function properly.

OK. So let's assume the knock sensor is operating correctly, and the ECU is not faulty, and there are no bad grounding wires. Here's my question:- Can a component , when failing intermittently, cause the engine to knock and thus the knock sensor to detect knocking? If so, what would those components be?

I read a while back that the knock sensors have approximately 4meg ohm of resistance. I also read they may have 30 meg ohm. What do they have for resistance?

What I thought I might do is disconnect the knock sensors at the connector, and then put the proper resistance across the connectors on the wire harness. What effect might this have? I don't know!! I'm hoping the ECU is NOT faulty and never gets trip by a knock code again.

Input welcomed.

Thanks,
RickM