P0330 Code

[worldly traveler]

I have read through most post on here and need help.....Have 98 Lexus ES300 that recently coded P0330 which I know is knock sensor. Looking through these post, many have had overdrive problems and lack of power. I have no such issues leading to the question is there something else that could cause fault code to appear? the car runs great and there is no difference in driving after code has been erased. After erasing and driving a few miles code reappears, but like I stated no diffrence in performance. Gurus, what else could cause this coding and how can I confirm that knock sensor or harness may be bad? What are some of the checks or test that can be done before tearing into the engine to confirm?

[rushlvr]

I just replaced the knock sensors in my 99. The car was driving okay, but periodically the RPMS would climb. The knock sensor causes the tranny to not go into OD. THe knock sensors are located underneath the intake manifold, and cost about 160 to 180 each. You must also replace about 3 gaskets. I also had the Harness replaced because heat had made it brittle, and the ends snapped just from being touched. New harness was 35 dollars. 600 to 700 dollars to replace the above mentioned items at my independent lexus mechanic shop.

[George_Jetson]

One easy way to determine if the is the sensor, or the ECM is to swap the wires at the EC1 connector. This is located at the end of the cylinder head, on the trany end. There are two wires on this connector, one for each of the sensors. If you swap the wires, and the codes changes to P0325, then you know that the sensor, or the wire connected to the sensor is bad.

At this point you could just jumper both wires to the working sensor. The two sensors are located just a inch or two apart. If one sensor picks up indications of pre-ignition, it is a safe bet that the other sensor is also picking up signals.

[lexis lexus]

George,

This is an interesting topic, made valuable, as replacing the knock sensors is a labor and part intensive exercise.

Here's where I get confused. I'm not sure what happens after the sensor picks up predetonation, but I assume the computer makes an adjustment in timing, airflow, fuel flow or some other function to minimize the knock. This may not be an abnormal event.

But when a code or codes are thrown, does this indicate knocking taking place, or does it mean there is a problem in the circuit, such as bad sensor or wiring sending abnormal or absent signal?

Phil

[George_Jetson]

Both P0325 & P0330 are for the absence of a signal from the knock sensors. The knock sensors are a pizo electric crystal, that generate a voltage when mechanically stressed. IE, it picks up vibration, and generates a voltage according to the amount of vibration. Since knocking is just a stronger vibration, it will generate a larger voltage. So with this in mind, you can deduce that there should be a signal any time the engine is running.

So these codes stand for the absence of a signal from one of the sensors. On some cars (such as some of the older chevy v8's), you could test the sensor function by LIGHTLY hitting the block with a hammer, near the sensor, while monitoring the timing. The computer should pick up the hammering and interpret it as knocking, and !Removed! the timing.

Once you have swapped the wires, and determined if the sensor / wire attached to the sensor is bad, you then need to determine if it is worth the hassle to repair it, or just jumper the signal from the good sensor, to both inputs. I know people will have their different opinions, BUT when this problem happens on my car, I assure you that I will install a jumper. Of course some day the other wire/sensor may fail, and then you will need to pull the manifold and repair it.

There is one other thought that I have read about. Some people will just jury rig a bracket on the end of the engine (using one of the engine to trany bolt). And bolt a sensor to this bracket. Since you would assume that any knocking would transmit throughout the entire block, you should still pick up the knocking. I would tend to agree with this logic, but I personally feel that jumping both signals is good enough.

[capnfred]

Interesting concept, will try that, I replaced the harness on my 93, but still get the error will try and jump the two and see what happens.. since the sensors are high impedance devices it should not affect the ecu.... thanks will let you know the results... btw on the 93 the two sensors are connected by only one connector.... thanks again

capn

[igbeserk]

i have a 95 es300. both sensors are connected by two separate wires. i had the 0325 error code before which is the bank 1 knock sensor, replaced it reset the codes and it still came back up. to bridge it wouldn't i have to splice the cable from the first bank to the second bank? and if that's the case i'd have to open it up all the way again i believe.

[George_Jetson]

i have a 95 es300. both sensors are connected by two separate wires. i had the 0325 error code before which is the bank 1 knock sensor, replaced it reset the codes and it still came back up. to bridge it wouldn't i have to splice the cable from the first bank to the second bank? and if that's the case i'd have to open it up all the way again i believe.

On the 98 lexus, there is a connector (EC1) for the knock sensors. It is located at the rear of bank 1 near cylinder #5. This provides a very easy asscess point to jumper the wires and do troubleshooting without having to remove the intake manifold.

[lexis lexus]

Both P0325 & P0330 are for the absence of a signal from the knock sensors. The knock sensors are a pizo electric crystal, that generate a voltage when mechanically stressed. IE, it picks up vibration, and generates a voltage according to the amount of vibration. Since knocking is just a stronger vibration, it will generate a larger voltage. So with this in mind, you can deduce that there should be a signal any time the engine is running.

So these codes stand for the absence of a signal from one of the sensors. On some cars (such as some of the older chevy v8's), you could test the sensor function by LIGHTLY hitting the block with a hammer, near the sensor, while monitoring the timing. The computer should pick up the hammering and interpret it as knocking, and !Removed! the timing.

Once you have swapped the wires, and determined if the sensor / wire attached to the sensor is bad, you then need to determine if it is worth the hassle to repair it, or just jumper the signal from the good sensor, to both inputs. I know people will have their different opinions, BUT when this problem happens on my car, I assure you that I will install a jumper. Of course some day the other wire/sensor may fail, and then you will need to pull the manifold and repair it.

There is one other thought that I have read about. Some people will just jury rig a bracket on the end of the engine (using one of the engine to trany bolt). And bolt a sensor to this bracket. Since you would assume that any knocking would transmit throughout the entire block, you should still pick up the knocking. I would tend to agree with this logic, but I personally feel that jumping both signals is good enough.

George,

Very interesting and now much more clear. Thanks.

So I have both sensor codes (P0325 & P0330) showing up, making me think wiring all the more. Jumpering not a fix in this case I'd think, but externally mounted knock sensor might.

I haven't taken a look to see if the connection is intact at EC1, this may be the simple solution. But if it isn't (the solution) may chase the wiring back to the ECU.

L

[worldly traveler]

UPDATE: I made jumper to test for knock sensor which code was not pulling. That sensor did not code while driving. After testing sensor, I made a quick fix by splicing into the lead going to knock sensor that was not coding. Fingers crossed, code was cleared and has not returned and this has been since initial post. After running the car with code off, the difference in performance was noted. I am sure eventually the other sensor will go out and end up replacing both at that time, however this bandaid is sufficient for time being.

Both P0325 & P0330 are for the absence of a signal from the knock sensors. The knock sensors are a pizo electric crystal, that generate a voltage when mechanically stressed. IE, it picks up vibration, and generates a voltage according to the amount of vibration. Since knocking is just a stronger vibration, it will generate a larger voltage. So with this in mind, you can deduce that there should be a signal any time the engine is running.

So these codes stand for the absence of a signal from one of the sensors. On some cars (such as some of the older chevy v8's), you could test the sensor function by LIGHTLY hitting the block with a hammer, near the sensor, while monitoring the timing. The computer should pick up the hammering and interpret it as knocking, and !Removed! the timing.

Once you have swapped the wires, and determined if the sensor / wire attached to the sensor is bad, you then need to determine if it is worth the hassle to repair it, or just jumper the signal from the good sensor, to both inputs. I know people will have their different opinions, BUT when this problem happens on my car, I assure you that I will install a jumper. Of course some day the other wire/sensor may fail, and then you will need to pull the manifold and repair it.

There is one other thought that I have read about. Some people will just jury rig a bracket on the end of the engine (using one of the engine to trany bolt). And bolt a sensor to this bracket. Since you would assume that any knocking would transmit throughout the entire block, you should still pick up the knocking. I would tend to agree with this logic, but I personally feel that jumping both signals is good enough.

George,

Very interesting and now much more clear. Thanks.

So I have both sensor codes (P0325 & P0330) showing up, making me think wiring all the more. Jumpering not a fix in this case I'd think, but externally mounted knock sensor might.

I haven't taken a look to see if the connection is intact at EC1, this may be the simple solution. But if it isn't (the solution) may chase the wiring back to the ECU.

L

[igbeserk]

cool glad to hear it. my car has been at the mechanics. he claimed he got rid of the check engine light. hopefully he didn't reset it with a scanner and thinks all is good LOL. but yea will try it when i get home and hopefully yea it doesn't come back.

[George_Jetson]

UPDATE: I made jumper to test for knock sensor which code was not pulling. That sensor did not code while driving. After testing sensor, I made a quick fix by splicing into the lead going to knock sensor that was not coding. Fingers crossed, code was cleared and has not returned and this has been since initial post. After running the car with code off, the difference in performance was noted. I am sure eventually the other sensor will go out and end up replacing both at that time, however this bandaid is sufficient for time being.

Both P0325 & P0330 are for the absence of a signal from the knock sensors. The knock sensors are a pizo electric crystal, that generate a voltage when mechanically stressed. IE, it picks up vibration, and generates a voltage according to the amount of vibration. Since knocking is just a stronger vibration, it will generate a larger voltage. So with this in mind, you can deduce that there should be a signal any time the engine is running.

So these codes stand for the absence of a signal from one of the sensors. On some cars (such as some of the older chevy v8's), you could test the sensor function by LIGHTLY hitting the block with a hammer, near the sensor, while monitoring the timing. The computer should pick up the hammering and interpret it as knocking, and !Removed! the timing.

Once you have swapped the wires, and determined if the sensor / wire attached to the sensor is bad, you then need to determine if it is worth the hassle to repair it, or just jumper the signal from the good sensor, to both inputs. I know people will have their different opinions, BUT when this problem happens on my car, I assure you that I will install a jumper. Of course some day the other wire/sensor may fail, and then you will need to pull the manifold and repair it.

There is one other thought that I have read about. Some people will just jury rig a bracket on the end of the engine (using one of the engine to trany bolt). And bolt a sensor to this bracket. Since you would assume that any knocking would transmit throughout the entire block, you should still pick up the knocking. I would tend to agree with this logic, but I personally feel that jumping both signals is good enough.

George,

Very interesting and now much more clear. Thanks.

So I have both sensor codes (P0325 & P0330) showing up, making me think wiring all the more. Jumpering not a fix in this case I'd think, but externally mounted knock sensor might.

I haven't taken a look to see if the connection is intact at EC1, this may be the simple solution. But if it isn't (the solution) may chase the wiring back to the ECU.

L

Good, hopefully the other sensor will keep you going for a long time. I don't really understand why they placed two sensors on the engine, especially when they are so close together. I think it is overkill, but at least it allows for this type of band-aid.

[igbeserk]

bleh error codes came back i think all he did was reset it. i gotta look at the haynes manual because i really couldn't see the EC1 thing you were referring to.

[worldly traveler]

bleh error codes came back i think all he did was reset it. i gotta look at the haynes manual because i really couldn't see the EC1 thing you were referring to.

I used a circuit tracer to find wire plugging into EC1. The EC1 was behind the glove box (must be removed) and had 4-5 plugs of multiple wires plugged into it. I made my jumper next to the manifold (drivers side) where the wire splits to the two sensors. There are two plugs (one for bank 1 and the other is bank 2). I just unplugged one of them and used wire to make my temporary jumper to find right sensor. Clear codes and drive. It took less than 1/2 mile before mine recoded. After finding bad sensor wire harness, I just cut into wire close to plug and tied in bad sensor wires to it and electrical taped the splice.....been working fine ever since.

[fpny]

Can you tell me exactly where the EC1 connector is located, I can seem to find it on my 97 ES300? I spent almost an hour looking for it, what color is the connector? Thanks.

[ff1113km]

Hello,

I am new to the forum and also have the same issue with my 2000 ES300. The car is currently at the transmission shop due to the transmission not going into OD while the wife was driving it on a 2 hour road trip. The mechanic stated that the he will get the transmission repaired but the problem is with the knock sensors.

I have been reading all the great information on this post but have a few questions. First, how do I find out which knock sensor is the "bad" sensor and second is it possible for anyone to post up a picture of the location and wires that I should be looking for?

Any help that I can get would be fantastic. We are planning on getting the car back on Saturday and I hope to have it up and running properly that day so my wife will not need to stay in the rental.

Thanks for your help.

[fpny]

How can you tell the car is going into OD or not? I am still looking for the EC1 connector and still can't find it. Attached is a wiring diagram from the ES300 service manual where the EC1 connector suppose to be located on the right side of the engine.

Hello,

I am new to the forum and also have the same issue with my 2000 ES300. The car is currently at the transmission shop due to the transmission not going into OD while the wife was driving it on a 2 hour road trip. The mechanic stated that the he will get the transmission repaired but the problem is with the knock sensors.

I have been reading all the great information on this post but have a few questions. First, how do I find out which knock sensor is the "bad" sensor and second is it possible for anyone to post up a picture of the location and wires that I should be looking for?

Any help that I can get would be fantastic. We are planning on getting the car back on Saturday and I hope to have it up and running properly that day so my wife will not need to stay in the rental.

Thanks for your help.

[ff1113km]

Well, a few weeks ago I was driving it on the highway and noticed that the RPM's were hanging around the 4300 mark. We made our stop and when we drove home, the RPM's were right around 2300 where I would expect them to be. I advised my wife to keep an eye on them since we just had the trans. rebuilt in late March. The rebuild came with a 12mo./ 12k warranty so they are rebuilding it as I type even though the general manager did state that there was a code showing that the knock sensors needed replaced which more than likely caused the damage to the trans. So, after a little research on the net and here, I have found that the knock sensors appear to place the vehicle in safe mode and I am hoping to do the fix by splicing the wires to the "good" sensor and get a little more time out of the vehicle. My wife loves that car and I would like to be able to trust it to cart the kids around without any problems. I hate to think that they are all stuck on the road somewhere in this 100 degree Texas weather. Thanks again for everyones input.

[jerryp]

Both P0325 & P0330 are for the absence of a signal from the knock sensors. The knock sensors are a pizo electric crystal, that generate a voltage when mechanically stressed. IE, it picks up vibration, and generates a voltage according to the amount of vibration. Since knocking is just a stronger vibration, it will generate a larger voltage. So with this in mind, you can deduce that there should be a signal any time the engine is running.

So these codes stand for the absence of a signal from one of the sensors. On some cars (such as some of the older chevy v8's), you could test the sensor function by LIGHTLY hitting the block with a hammer, near the sensor, while monitoring the timing. The computer should pick up the hammering and interpret it as knocking, and !Removed! the timing.

Once you have swapped the wires, and determined if the sensor / wire attached to the sensor is bad, you then need to determine if it is worth the hassle to repair it, or just jumper the signal from the good sensor, to both inputs. I know people will have their different opinions, BUT when this problem happens on my car, I assure you that I will install a jumper. Of course some day the other wire/sensor may fail, and then you will need to pull the manifold and repair it.

There is one other thought that I have read about. Some people will just jury rig a bracket on the end of the engine (using one of the engine to trany bolt). And bolt a sensor to this bracket. Since you would assume that any knocking would transmit throughout the entire block, you should still pick up the knocking. I would tend to agree with this logic, but I personally feel that jumping both signals is good enough.

[jerryp]

I have a 1996 300es and I have a PO330 code, I was thinking about jumping to the good sensor. I have found the connector (I think) and I have unpluged it and it has 4 wires on the female end and only two wires on the male end going to the knock sensors. Can you tell me how to make the jumpers and to which pins on the 4 wire plug.