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P0330 / not replacing knock sensor

73K views 23 replies 10 participants last post by  PasadenaGeek 
#1 ·
#3 ·
I think that knock sensors can detect inaudible to human ear knocks (pre-ignition detonation), you won't hear that, you will just feel effects of it when ECU reacts to those and retards timing or goes into a limp-mode.

the code P0330 means that ECU commenced a maximum timing retardation to prevent any possible damage to engine, because it lost signal from knock sensor. this behavior gets returned to normal with ignition switched off, so you don't even need to reset the ECU probably.

P0330 = Knock Sensor 2 Circuit Malfunction

DTC detection condition:
No knock sensor 2 signal to ECM with engine speed between 2,000 rpm and 5,600 rpm.

Trouble area:
-Open or short in knock sensor 2 circuit
-Knock sensor 2 (looseness)
-ECM

gas mileage usually goes down when this happens a lot and ECU falls into a limp mode because of it every time (until you cycle ignition).

apart from bad sensor, it could very well be a problem with wiring to the front bank's knock sensor. have you checked the plug already, maybe it's just loose?
 
#4 ·
You should replace both knock sensors and also the wiring harness to the knock sensors. Murphy's law states that if one of the two knock sensors is bad and you only replace the one, then the other will go bad in a week. Seriously, the other one is just as old and could fail at any time

These knock sensors are critical, so they should be replaced when a fault code for their failure sets.
 
#5 ·
These knock sensors are super sensitive, but usually don't go bad. They're also super expensive.

You have either a bad wiring harness or a bad knock sensor, there is no CEL if it determines a knock. Start by checking the sensor for tightness. You'd need an oscilloscope to test it's function, though. You can test the wire/connector.

I would replace the sensor. You'll need the Denso sensor as the other, in my experience, do not work. I got mine from Carquest for $190.
 
#7 · (Edited)
These knock sensors are super sensitive, but usually don't go bad. They're also super expensive.
I have a whole box of faulty knock sensors that tells otherwise. I've replaced them on Chevy, Cadillac, Nissan, Infiniti, Toyota.

Especially Nissan/Infiniti 3.0V6 like in the Maxima and I30 They even give you the connector and pigtail, since the connection on these must be clean and tight. My big mitts can barely reach under the intake manifold to get to the knock sensor on these, but if I have to replace one in a Pathfinder or other vehicle where the engine is not transverse, then major disassembly is in order.

Oh, DENSO only please.
 
#8 ·
thanks guys appreciate it, yeah I'm going to have a nice big job ahead of me, I have some engine leaks im going to try and fix too, by replacing the rear valve cover gaskets,

and yep thats what I been told too replace both knock sensors,

am I able to check the wire tightness before I start operation or I have to remove the manifold for that?
 
#9 ·
am I able to check the wire tightness before I start operation or I have to remove the manifold for that?
If you're asking about the connections at the knock sensors, no, there's no way to get a hand in there to check without removing the intake plenum and intake manifold.
 
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#11 ·
Yep. And there are two knock sensors, one mounted on each bank. You can see one of 'em in this pic, left of the coolant bypass hose. The other is blocked from view by the hose.

 
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#18 · (Edited)
Why would I cut the wires? I don't know what's wrong yet. Either the wire is messed up or just the knock sensors in bank 2 is malfunctioning. Do I have to take off the intake manifold to get to the sensors or to test them is another question? Tell me what you decides to do and if you have pictures or whatever to do it will be great.
 
#22 · (Edited)
BOTH sensors showing codes at same time?

I recently got done with a valve cover gasket job and now I get odbII codes (po330 and po325), the car seems to run fine however. I've cleared the codes multiple times but they come back after 5-10 minutes of road time.

Any clues as to what is going on?
 
#23 ·
I recently got done with a valve cover gasket job and now I get odbII codes (po330 and po331), the car seems to run fine however. I've cleared the codes multiple times but they come back after 5-10 minutes of road time.

Any clues as to what is going on?
Perhaps the connector is unplugged?... The one attaching the short cable to the main wiring harness.
 
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#24 ·
I just replaced the Bank 2 sensor and harness (per recommendation of a Toyota tech) on my 01 Highlander with the 1MZ-FE. It's not difficult with small hands... I also got a kit with all the intake manifold gaskets - that at 178,000 miles, didn't really need, but considering what it's sealing, I replaced the gaskets anyway. About 7 hours to tear down the intakes and manifolds, 2 hours for the sensor and harness replacement (I was tired, and I couldn't get the end of the harness off the cable bundle, about 15 minutes of real work), and 2 hours to out everything back (don't forget the grounding wire on the back of the upper manifold!). Just waiting for Evap or Cat to go ready for the yearly Texas inspection!
 
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