P0330 Knock Sensor, 15 min. Hack Repair...
Racer
Joined: Oct 2009
Posts: 1,289
Likes: 319
From: nj
Sadly the hack would not work for me. Seems that both knock sensors have died at 153k miles. And... having to drive any distance in "limp mode" is a frightening experience. Top speed was 53MPH. Plus the moaning and groaning from under the hood.
I was stuck with having to use the interstate. Damn car would hardly get out of its own way. Scary.
Time to shell out the big bucks. Rats.
I was stuck with having to use the interstate. Damn car would hardly get out of its own way. Scary.
Time to shell out the big bucks. Rats.
Seems odd. You only reported P0325 which is knock sensor #1. If both were bad (or it was the wiring harness) it should have given you P0330 too. The circuits are independent. This hack disconnects the bad sensor input and splices the signal from the one good one to feed both of the ECU inputs. Is it possible you didn't get the splice right?
Rookie
Joined: Jul 2025
Posts: 25
Likes: 3
From: Wisconson
You should keep a code reader in the car to clear the codes when you need to.
Seems odd. You only reported P0325 which is knock sensor #1. If both were bad (or it was the wiring harness) it should have given you P0330 too. The circuits are independent. This hack disconnects the bad sensor input and splices the signal from the one good one to feed both of the ECU inputs. Is it possible you didn't get the splice right?
Seems odd. You only reported P0325 which is knock sensor #1. If both were bad (or it was the wiring harness) it should have given you P0330 too. The circuits are independent. This hack disconnects the bad sensor input and splices the signal from the one good one to feed both of the ECU inputs. Is it possible you didn't get the splice right?
And I tried the code reader in the car. Didn't work for me. I left it connected and would clear it at times (hooked up to an already running engine) but, al;though the reader said it was clear, and the CEL went off, no change in engine behavior.
Last edited by HadYourPhil; Sep 30, 2025 at 07:15 PM.
Racer
Joined: Oct 2009
Posts: 1,289
Likes: 319
From: nj
Sorry, guess I forgot to mention that I got both codes. As electronics is my line of work, it is doubtful I got the splice wrong. Right now, I have sensor two going to both inputs. Althouigh I have gotten the 0325 code, I will try the hack on that sensor.
And I tried the code reader in the car. Didn't work for me. I left it connected and would clear it at times (hooked up to an already running engine) but, al;though the reader said it was clear, and the CEL went off, no change in engine behavior.
And I tried the code reader in the car. Didn't work for me. I left it connected and would clear it at times (hooked up to an already running engine) but, al;though the reader said it was clear, and the CEL went off, no change in engine behavior.
Both could be the connector or the wiring harness. The connector is roughly under the throttle body area.
It seems odd the engine would be in limp mode before showing a code.
Racer
Joined: Oct 2009
Posts: 1,289
Likes: 319
From: nj
Rookie
Joined: Jul 2025
Posts: 25
Likes: 3
From: Wisconson
Questions and clarifications
The Knock Sensor thread continues... I have an '01 RX300 with the 0325 and/or 0330 codes. Oddly the code is not always combined with the same limp mode result. The worst one was having to drive from Milwaukee to Manitowoc in Third gear at a maximum speed of 53MPH. That was a few weeks ago. I cleared the code and reconnected the wiring hack and the car was fine for several days. Then, on comes the CEL and no shifting into fourth. However, the engine is running fine!.
Now, on to the knock sensors. In post 193, Maxsteel correctly describes the testing procedure as par the Diagnostics described on pages DI63 to DI65 of my service manual (it''s on a CD). On post 223, the correct voltages are described. The voltage generated by the KS is minuscule so it is easy to think a dirty connector could be the cause. In fact, my manual lists "looseness" as a possible problem. Problem there is, most likely the "looseness" is at the Knock Sensor. No short cuts.
The most interesting post comes from Bobwatt, #232, where he clampted a sensor to some place on the intake manifold, allowing the sensor to "hear" the voltage developed by the KS, His referenced post about a 2001 Toyota Harrier had more detail and pictures (which I haven't been able to discern yet).
Unfortunately, in post 267, 350Zguy didn't have luck with Bobwatt's clever solution. However, he didn't use a Denso sensor but a Dorman one. So... My question is... did the Bobwatt cure work long term? Or did it not work as per 350Zguy? I have PM'ed Bobwatt but no reply.
I would pose the manual's procedure but I get the feeling that may be a copywright violation of some sort.
Hope you enjoyed my album length post! Apologies for any typos.
Now, on to the knock sensors. In post 193, Maxsteel correctly describes the testing procedure as par the Diagnostics described on pages DI63 to DI65 of my service manual (it''s on a CD). On post 223, the correct voltages are described. The voltage generated by the KS is minuscule so it is easy to think a dirty connector could be the cause. In fact, my manual lists "looseness" as a possible problem. Problem there is, most likely the "looseness" is at the Knock Sensor. No short cuts.
The most interesting post comes from Bobwatt, #232, where he clampted a sensor to some place on the intake manifold, allowing the sensor to "hear" the voltage developed by the KS, His referenced post about a 2001 Toyota Harrier had more detail and pictures (which I haven't been able to discern yet).
Unfortunately, in post 267, 350Zguy didn't have luck with Bobwatt's clever solution. However, he didn't use a Denso sensor but a Dorman one. So... My question is... did the Bobwatt cure work long term? Or did it not work as per 350Zguy? I have PM'ed Bobwatt but no reply.
I would pose the manual's procedure but I get the feeling that may be a copywright violation of some sort.
Hope you enjoyed my album length post! Apologies for any typos.
Last edited by HadYourPhil; Nov 1, 2025 at 03:36 PM.
Racer
Joined: Oct 2009
Posts: 1,289
Likes: 319
From: nj
I did it 11 years and 130k miles ago. I had previously replaced the sensors with Denso sensors and replaced the harness but a few months later it was acting up again. The hack requires at least one good signal coming to the ECU, so you may have to chase the wiring. It should be easy to check the continuity from the ECU to the knock sensor harness connector. Sucks from there to the sensors.
Rookie
Joined: Jul 2025
Posts: 25
Likes: 3
From: Wisconson
So you are saying you did the physical mounting of a sensor on the intake manifold? I have a signal tracer so finding the wire from the ECU to the KS connector near the intake should be relatively easy. I would love to see a good picture of the KS mounting.
If this is as described, and it works, this would be a "hack" thar would still give the ECU information it is looking for. A great cure! And a lot less work and expense!
Thanks for your response.
If this is as described, and it works, this would be a "hack" thar would still give the ECU information it is looking for. A great cure! And a lot less work and expense!
Thanks for your response.
Racer
Joined: Oct 2009
Posts: 1,289
Likes: 319
From: nj
So you are saying you did the physical mounting of a sensor on the intake manifold? I have a signal tracer so finding the wire from the ECU to the KS connector near the intake should be relatively easy. I would love to see a good picture of the KS mounting.
If this is as described, and it works, this would be a "hack" thar would still give the ECU information it is looking for. A great cure! And a lot less work and expense!
Thanks for your response.
If this is as described, and it works, this would be a "hack" thar would still give the ECU information it is looking for. A great cure! And a lot less work and expense!
Thanks for your response.
1st Gear
Joined: Nov 2025
Posts: 1
Likes: 0
knock sensor #1 and #2 pin locations for 2004 Rx330
This is for the people that don't want to pay big money to replace a bad knock sensor. I got the dreaded P0330 code saying the #2 knock sensor circuit was bad. I was driving 46 miles each way to work and had to stop and reset the light before I could there because she went in limp mode and I would lose overdrive. I just had to remove all of the same stuff to replace my leaking valve covers just a couple of months ago. I did not want to do that again. The ecu is looking for a small voltage between a set range to decide if that is normal and won't throw a code as long as it sees that voltage for each sensor. So I decided that since there are 2 sensors, and only one is bad right now, I will just feed both sensors from the good #1 bank sensor and the ecu will be happy. So i cut the wire feeding the #2 sensor and spliced it into the #1 sensor at the ECU. Anyway, it took me 15 mins and NO money to fix it. She drives as good as ever and no more CHECK ENGINE LITE. Im not telling anyone to do it, im just telling you what i did so you do what you will or won't. 
Don't Hate!
Don't Hate!
Driver School Candidate
Joined: Jun 2018
Posts: 20
Likes: 5
From: VA
Salim is going to hate me, my RX300 spent almost 4 years with the 330 error code. Then a few months ago the 325 error code also appeared (engine ran rough when cold).
Since there were too many error codes to pass inspection due later this year, I finally had my mechanic replace both knock sensors.
1999 RX300 with 377,841 miles on the odometer.
Since there were too many error codes to pass inspection due later this year, I finally had my mechanic replace both knock sensors.
1999 RX300 with 377,841 miles on the odometer.
CL Community Team
Joined: Apr 2001
Posts: 16,503
Likes: 1,369
From: Austin, TX
Salim is going to hate me, my RX300 spent almost 4 years with the 330 error code. Then a few months ago the 325 error code also appeared (engine ran rough when cold).
Since there were too many error codes to pass inspection due later this year, I finally had my mechanic replace both knock sensors.
1999 RX300 with 377,841 miles on the odometer.
Since there were too many error codes to pass inspection due later this year, I finally had my mechanic replace both knock sensors.
1999 RX300 with 377,841 miles on the odometer.
I am glad your problem is behind you.
Salim
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