If anyone wants to do this please send a phone number and I'll text a pic of the splice. Its not that the splicing is difficult, buy knowing what wires to splice was the biggest gamble. I found the information on another forum and followed the lead of quite a few 3UZ folks dealing with some old, hard and broken wiring.

 

If the engine is going to knock, it would knock on both banks of cylinders, so using one knock sensor makes sense, at least in theory. Perhaps a little unorthodox for most, but if you're good with it, that's all that matters. Hope that the wire connection for the one sensor you're relying on now for both cylinder banks remains solid. Great improvised solution.

What grade of gas do you typically run?

 

Can you upload a pic? And describe location (or another pic) of the ecu that you tapped into behind the driver's side headlight? And the link to the other forum you relied on?

 

I almost always burn premium fuel.



This is the pin out that I used to identify the correct wires. If you are wanting a pic of the splice please pm with your email and I'll send you a pic from my phone.

This is one of the many discussions that helped me get the courage to do the work around.

http://us.lexusownersclub.com/forums...-knock-sensor/

The ecu is in a water tight case directly behind the drivers headlamp. After removing the right side cover closer to the firewall, take the top off the case with three 10mm bolts. The ecu is obvious but if you haven't seen one, go ahead and google so you are familiar with it. Its a metal case that is mounted vertically so the wires are handy.

 

Tom, exactly my hope with the good wire from bank 2. I have not found in researching this P0325 code that the corresponding code for bank 2 comes up nearly as often, so perhaps I'll be able to hold out for a bit.

 

By the absence of the DTC returning, you seem to have isolated the "Bank 1 knock sensor" problem to either the knock sensor itself, or the section of wire between the sensor and the new splice you've installed.

This hack bypasses the detection of a bad knock sensor circuit and thus eliminates the Check-engine light. But disabling the warning detection functionality does nothing to address the problem.

Engine knocks occur when the ignition timing is off (early detonation). The LS430 ECM monitors its 2 knock sensors (Bank 1 and Bank 2) and adjusts the ignition timing, as well as the two VVT (Bank 1 and Bank 2, independently) to minimize knocks.

Feeding the ECM with Bank 2 knock sensor signal to control engine knock occurring in Bank 1 will not yield the desired benefit (most likely making situation worse). Typically, you will experience some reduction of fuel MPG, and perhaps a slight reduction in power when you try to accelerate while driving highway speed.

Engine knock is not an emergency. Improper timing, if persisted, can cause some undue wear-and-tear to your engine parts. You should consider making the repair sooner rather than later, especially if you want to keep your LS operating at peak condition, and for its longevity.

 

Invest in the engine by changing the sensor. Period, no short way of doing it.

Heck, I couldn't even do that hack to my ES, let alone mess with with the mighty 3UZ.
I am not sure how much more it would cost on the 430. But I did all the work by myself on my ES, and the sensors were around $90-$100 a pop.


Like my brother RKW mentioned, covering the light will not solve the problem, it'll still be there, you'll just forget that you have a problem.


Think of it this way, would you rather spend a couple bucks on it now, get the issue fixed and live stress free?
Or by testing your luck for now, but end up regretting this in the near future. It might save you the money right now, but you will be destined to pay it, maybe even 2-3 times more.

Brotherly advice.

 

It's most likely NOT the knock sensor. Many have reported code P0325 is typically a bad wire connection / harness on Bank 1. Many with the GS430 and LS400 have tapped into one knock sensor with no negative collateral affects.

The OP would be most likely to have a knock issue if / when there's a faulty fuel injector on Bank 1 (the bank relying on the opposite side knock sensor for knock detection). The best course of action is to replace the harness / fix the connection to the knock sensor - as well as replace the sensor while you're there. But, there wouldn't be any noticeable difference in performance or gas mileage running on one knock sensor through the normal RPM range (and assuming premium gas). While the VVTi are ecu-controlled variably together with crank/spark timing, knock detection readings from the "good" sensor for the Bank 2 cylinders will not significantly differ from knock detection readings for the Bank 1 cylinders. In other words, if there's knock detected on Bank 2 by the working knock sensor, then knock would also be detected on Bank 1 if it had its own working Bank 1 knock sensor, but instead it's relying on the Bank 2 knock sensor for feedback.

 

RKW, I totally hear you and the advice, which is solid. You too, King. I'm not often a short-cut guy. However, I really don't want to sink500-600 in parts plus labor (me or my mechanic) right now. My gamble is that, as Tom has said, my problem is not a knocking motor but faulty wiring. I banked on faulty wiring and I could be right.

The car has 141k, it is my daily driver, but I also have some other hobbies to feed (couple of Harleys, M3, RX350, a kid in college, a kid getting married and a trip for 10 to Disneyland on my dime. If I could insert an emoji of me crying I would. LOL

 

Thank you, Revrun, for the follow-up... Agree 100% on the budget-balancing bit - so true! As I said, this is not an emergency.

 

My advice came out mostly like that because I just didn't want you to forget about it, the hack that is. I assumed you're a general every day user, and that's why I would never recommend such a bypass trick.

But hey, I understand budgeting, and sometimes you just need to organize you're spending dependent on priority level of what's currently going on in your life, I understand that. So if you know for sure that you'll have time to get back to it then I don't see why not.


My ES had the same issue, and I think the previous owner daily drove it like that for almost a year. Sometimes it is a faulty connection. On the ES I could've gotten away with just changing the wire harness that goes on the sensor, because that's what usually goes out and not the sensor itself.

Good luck to you

 

Just a quick follow-up. Car is running great. No cels of any kind. Fuel economy is normal. I used to get P0325 at start-up in the morning. Or as quickly as 1 min after erasing the code . Or sometimes after an hour of driving. In other words, there was no rhyme or reason to when it would throw the code. But it was getting more frequent. I'll update again in a few months.

 

Not surprising ... many engines have only one knock sensor.

 

OP I sent you a PM, hope you are still on the board.

 

Sent you a PM, I replaced the Bank 1 sensor and it's still doing the same thing (with the notied issues driving), I am willing to attemp this hack as I need the car running good and pulling it apart again to attempt do the wiring sounds like a possable nightmare (it took about 5-6 hours to do and about $200 in parts).

With your results and no reply of bad issues, seems like a nice work-around here.

If anyone got the picture he was sending send it to <my user name> @hotmail.com

Thanks !