Knocks Sensor Low Voltage

[gpr]

I am working on a 2002 Chevy Silverado with the 5.3l. I keep getting error codes P0327 and P0332, which are low voltage to knock sensors on bank 1 and 2. It seems as if the knock sensors aren't working at all as i never get any knock when i am scanning as i drive, and I use to get little flairs of knock here and there.

I was modifying my exhaust just before this problem started and i was wondering if the voltage that goes to the knock sensors are on the same circuit as the o2 sensors behind the cats? I unpluged one of the post cat sensors as when i modified the exhaust i stripped the o2's threads and didn't want to buy a new sensor.

So does the voltage for the post cat o2's use the same as the knock sensors? Also where are the knock sensors located on these engines, I couldn't find it when I was looking today.

thanks for any and all help

[Mr. P.]

I did this once, crawling atop the engine to swap transmissions I unknowingly popped the connector loose and unplugged them! Check the connector, located at the driver's rear of the intake manifold, just above the PCV line.

Mr. P.

[gpr]

I wasn't on top of the engine messing around but i will check to make sure all connectors are plugged in and okay.

I was talking with one of my mechanic buddies and he was saying he has seen problems with the knock sensors going bad if you are in a lot of water or mud. says it can get in there some how and rust the sensors causing them to go bad. I just don't see how that is possible both of them went bad almost at the same time....

[Mr. P.]

I wasn't on top of the engine messing around but i will check to make sure all connectors are plugged in and okay.

I was talking with one of my mechanic buddies and he was saying he has seen problems with the knock sensors going bad if you are in a lot of water or mud. says it can get in there some how and rust the sensors causing them to go bad. I just don't see how that is possible both of them went bad almost at the same time....

He's right - we have seen that as well. Because the knock sensors are screwed into the valley cover (under the intake manifold) they can trap water & muck and rot out. But I agree with you, it's not likely you'd have both of them fail on you at the same exact time.

Mr. P.

[Frost]

Also keep in mind, when this code is present, the vehicle will remove the maximum allowed amount of timing specified for KR in PE whenever going into PE.