Diagnosing this trouble code. Indicates that voltage is detected high for over 1 second coming from Bank 1 knock sensor. Sensor is absolutely buried and I unfortunately don't have the time luxury to repeatedly disassemble the intake chasing possibilities, so trying to eliminate as many root causes as I can before tearing apart the top of the engine to replace this 30 dollar part.

Sources indicate typical fail modes are the sensor, the wiring, or an ECU fault.

Ran test leads to wire taps I inserted into the red and green wires here just before the E5 plug at the ECU. Couldn't recreate this signal on my oscilloscope, and testing for voltage indicated about 2 volts on the green wire.

With the engine off and the plug removed from the ECU, I measured 200 kohms across knock sensor 1 and knock sensor 2. Suggests not a frayed wire.

One of the forum threads I checked out mentioned that this issue could be caused by capacitors failing in the ECU, with some (probably one) person claiming it could be resolved with replacing the caps (which I am prepared and qualified enough to do if it came to it). I don't have any more info on this fix, so if anyone has heard or read something, I'd love to know.

I de-pinned bank 1 knock sensor, and car through a voltage high code for bank 2 knock sensor. This lends toward an ECU issue, I think.

Today I experimented with depinning all 4 knock sensor wires. None had any voltage relative to their pair or to ground (frame). I then connected one of each pair back to the ECU and I then was able to measure around 4-5 volts on bank 1 and 2-3 volts on bank 2.

But I wanted to see if the community had any input or could offer some other simple low-intrusion tests I could perform to narrow down the issue. Second, what is the process for identifying an appropriate replacement ECU and then replacing it. Any special instructions?

if its the v8, thier known for critters crawling in between the intake where the knock sensors are and causing chaos, chewing cables etc. so might be worth taking a peak under that intake. its actually not that bad, once you do it the first time, you can do it in like 20 mins the other times. i had the v8 model 2 yrs ago and i replaced both of them, nothing chewed but you could tell something was in there before as their was cotton and leafs staked.

I should be able to peak, at least with a borescope. I feel like I've done enough continuity checks to comfortably assume the wiring is intact, but visual confirmation won't take much time.

Everytime I hear of a knock sensor issue it has been critter induced including the one on an Odyssey we used to have.

Yesterday, my CEL came on with code P0328. I read this post and others, and someone said get the diagram of where your sensors are. Found it. I am not a mechanic AT ALL and I did not want even take the plastic cover off to expose the engine top. I removed the air filter clamps and opened it to reveal the sensor. I tapped on the sensor with my finger then wiggled and tightened the wire harness connector. Problem solved, the CEL was off with no further action needed. Did a test drive, ran to the store, got kids from school - seems fixed! Good luck!

It is worthy of congratulations. I normally ask for any old parts to be returned to me rather than discarded. They should have held it till after you got your Lexus.