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.

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

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?

I'm no expert, and I don't have the answer for you, but I do have a thought

about what you might try. First off, the knock sensor shouldn't affect the

engine's performance if there is no engine knock situation present. You may

be getting the fault code because the computer can't find the knock sensor

on line.

I have frequently found that electrical problems are not the fault of the actual

part, but rather corrosion at the connector to the part. If you were to disconnect

the knock sensor wiring harness and clean up the contacts with electrical contact

cleaner (comes in a spray bomb with a 4 inch long spray tube, available at any auto

parts store)and reconnect the harness, you may find that it will fix your problem.

Be sure to do the cleaning with the engine off, and allow several minutes for the

cleaning fluid to evaporate before starting the engine.

Now to your second question ... where is the knock sensor located? On your model year

... I don't know. Hopefully someone will jump in with the answer for us both.

Good Luck!

Thanks for the input. I know that the 98 has two knock sensors that are located on the block. They are both located under the manifold and it is very extensive and time consuming to remove upper engine parts just to get to both sensors. I have tried to locate the harness that goes to the sensors and am unsure were they connect to ECM. My thoughts were to try and do a continuity check or swap the connectors to see if a code would come back or maybe the harness was bad. Any input or suggestions would be greatly appreciated on this type of check. I am trying to eliminate any other possibilities that underlining cause for code could be by product of some other issue I am unaware of.

Hi,

I recently picked up 96 es300 with the 1mz-fe v6, it came with code p0330 knock sensor bank 2. I rewired the knock sensors at the ecm so both would feed off bank 1 sensor and every thing seems fine for a while.

Cleared codes , and code p0125 was present cleared it.

Changed valve cover gaskets front and rear.

Drove car and code p0770 came up, trans shift solenoid E. I flushed transmission and reset code, came back up about 5 min of driving p0770 and a p0401 egr insufficient flow.

Do u think the engine computer might be bad or a bad ground? The trans shifts fine but it still through the p0770 code.

The engine harness someone who previously owned the car was poking around, i could see the knock sensor harnesses were pryed into.

It just dosen't make sense that these random codes pop up one after another with nothing aparent wrong to the car. I will double check all EGR and vaccum lines, but u think it might be a BAD ECU ?

any help appreciated.

How did you rewire (specifically) the knock sensor at the ecm? I want to try mine to see if that is actually the problem before tearing into the engine to replace them.

I recently purchased a 98 ES300 from a friend. The car is great shape and runs spectacular. Before purchasing the 100,000 mile service was completed and all was good. Since, the car has 4,500 miles added and the CEL has come on. The code was P0330 indicating the knock sensor. There is no indication of sluggish power, overdrive shifts great and functioning properly, etc. etc. Is there a test for the knock sensors to make sure that there is a problem before tearing into the engine?