Knock Sensors Rx300 2000

[timspell]

i had some transmission work done and it appeared they damaged the harness.

i removed the intake manifold then changed the harness and still have a 0330 fault (knock sensor circuit fault).

now that i have the old harness, is there a way to rewire the ends that go to the sensors to fool the computer.

or does anyone know the sensors work? do they create a resistance in the circuit or are they straight to ground?

[Ericok]

i had some transmission work done and it appeared they damaged the harness.

i removed the intake manifold then changed the harness and still have a 0330 fault (knock sensor circuit fault).

now that i have the old harness, is there a way to rewire the ends that go to the sensors to fool the computer.

or does anyone know the sensors work? do they create a resistance in the circuit or are they straight to ground?

It's a piezo electric device that generates a voltage in proportion to engine "knock" being detected. Shorting, grounding or adding reistance would only keep your check egine light permanently on since the engine computer wouldn't be seeing any voltage from the sensor. I presume you cleared the old error code after changing out the harness.

[timspell]

ericok

yes i cleared the code several times.

thank you for the info

that's it for this vehicle! off to the auction.

[Ericok]

There's 2 knock sensors on this vehicle. Code P0330 is on the left bank. There's only three things that can be wrong: knock sensor loose, wiring harness fault and ECM. It's almost always wiring. One thought, based on the circuit diagram, you could try running both ECM sensor wires to the "good" right-side sensor.

The other "good news" is that when this code is generated, the ECM goes into failsafe and sets the retarded ignition timing on max !Removed!. That means you should be able to use regular gas with no problem.

[timspell]

ericok

the big problem is that it will not shift into overdrive with this fault.

is the left bank the front bank.

i do not want to take that manifold off again.

do you mean splice the wires on the new harness where they are accessable. i will not be able to determine which wire goes to the left bank without taking the manifold off.

i could always do the trial and error method. to see which wire goes the the right sensor, or the good sensor.

have you tried this before

thanks tim

[Ericok]

Yes, the left bank is the front.

The only go-no go test for the knock sensor is if it's shorted between the terminal and body (shorted=bad). If you have a OBD II tool that can read the data stream there's a more elaborate test but it seems to be overkill. They do suggest reversing the knock sensors to see if code P0330 changes to P0325 - this confirms your problem is on the left side.

The shop manual shows a single white wire going from each knock sensor and connecting (through a plug) to a second wiring harness (which goes to the ECM computer). That second harness has two wires White and Black which connect to the ECM. The Black wire is bank 2 (left), the White is bank 1 (right).

Just to describe the plug: both knock sensors go to the male side of the plug. The female side continues to the ECM. Looking at the male side, there are 4 contacts numbered 1-4 starting at the upper left and going clockwise. The right hand sensor goes to contact 1 and the left hand sensor goes to contact 2. Contacts 3 and 4 look to be unused. You can do the sensor reverse test by using a couple of wires to cross connect the contacts (that's what the shop manual recommends).

I'm saying, since your desperate, connect the black wire to the white one. Now the computer gets both readings from the right hand knock sensor. You can try this at the plug without cutting any wires - assuming the plug is accessible.

No, I've never tried this before. This is based on the 2000 shop manual. It won't go into overdrive: book says ECM problem or O/D circuit bad (you should know it won't go into overdrive until the engine is warmed up - that's normal).

[wwest]

ericok

the big problem is that it will not shift into overdrive with this fault.

is the left bank the front bank.

i do not want to take that manifold off again.

do you mean splice the wires on the new harness where they are accessable. i will not be able to determine which wire goes to the left bank without taking the manifold off.

i could always do the trial and error method. to see which wire goes the the right sensor, or the good sensor.

have you tried this before

thanks tim

When the engine is operating in O/D it is on the "cusp" of lugging, lowest possible RPM at which the engine power output is just on the verge of not being enough to move the vehicle forward at the current roadspeed (piston cannot move downward as fast as the flame front is expanding).

So it makes sense that the engine ECU would now allow O/D gear ratio since it cannot reliably detect the onset of knocking/pinging.

[Mike's RX300]

I have the exact same problem and I would like to know where this harness is and is it accessible from the top of the motor? The left bank knock sensor is under the intake manifold and there is a wiring harness that comes out by the thermostat housing but I am not sure if I'm on the right track.

[Equsnarnd]

"So it makes sense that the engine ECU would now allow O/D gear ratio since it cannot reliably detect the onset of knocking/pinging."

Did you mean to say that or were you trying to say this?

"...the engine ECU would NOT allow the O/D gear ratio..."

Edited October 15, 2022 by Equsnarnd
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