Revrun

I'm trying to perform the bank 1 knock sensor hack to rid myself of code P0325. The hack involves connecting the good signal from the bank 2 knock sensor to the bank 1 wire as it goes into the ecm while leaving the bank 1 sensor disconnected via a cut wire.

I have seen a similar hack performed on the clublexus gs forum.

Has anyone done this? Any ideas on where to find the pinout on the ecm so I can perform this? Any other ideas or thoughts?

Thanks

rkw77080

Here's the pin-out diagram you requested. "Hacking" as you described does not fix your problem. Please be advised that you're proceeding at your own risk.



***UPDATE*** Go to Post #38 for pin-out information to combine knock sensors.

Revrun

Thanks for the pin out. Really appreciate it. What are your concerns?

Thanks

takimanpgt

Well - the knock sensor has a function in the engine and your bypassing it masks the original issue and also turns the knock sensor's function useless until you fix the issue.

But the heck is yours and yours only to make so go ahead. I don't think anyone is going to stop you. It is an expensive repair and we have two sensors so might as well try something out and see if it works.

Revrun

Yea. Kind of a gamble. I have read of a few that replaced both sensors only to have the code come back. Some on the GS forum have found this "trick" to be successful. Still considering the options.

rkw77080

Your ECM uses the feedback from the knock sensors to vary the VVT (Variable Valve Timing) and/or to alter the fuel-to-air ratio. When you receive code P0325, it means that the Bank 1 Knock Sensor is failing or there is something wrong with the circuitry. Without the input (feedback) from the knock sensor, the ECM will not be able to correct the abnormality. As takimanpgt already mentioned, hacking will only mask the code P0325, but does not address the potential problem.
Of course, a bad knock sensor (P0325) and having a knocking problem are 2 totally different issues. The point is that a properly working knock sensor automates the corrective action by the ECM in respond to the varying levels of knocks. That's right, the ECM continuously monitors the knock sensors to fine tune the VVT and fuel-to-air ratio settings.

Brewmyown

There's obviously a problem making it throw the code. Just because it's throwing a code for the knock sensor doesn't mean it's the knock sensor. It can just as likely be something causing the knock sensor to be out of spec and cause a code.

For instance, many times a code indicating a faulty O2 sensor ends up being an exhaust leak so rbeplacing the o2 sensor wouldn't fix the problem.

Research and troubleshoot the cause instead of masking it. If it's truly something causing a knock, it can lead to worse and more expensive problems.

isfdude

iTrader: (11)

I wouldn't run both monitors to one knock sensor. It won't run the same and will not have the same power or gas mileage.

Tom57

Clean the MAF and throttle body, as well as run fuel injector cleaner through the system. If necessary, run the commercial grade concentrated bottle of injector cleaner attached directly to the intake / throttle. P0325 has been solved this way on LS430's. Are you also getting a P1349 code? (This would indicate an oil control valve which is part of the VVT.)

Revrun

RKW, the diagram you kindly sent doesn't match up with my ecu. Mine has 5 sections (molex) in consecutive row with no space. The molexes themselves are shaped differently. Any other ideas? Thanks so much.

Tom57

Have you tried swapping/switching the knock sensors to isolate the code to a specific knock sensor? https://www.clublexus.com/forums/gs-...nsor-code.html

Many have found it's the wiring / connections to the knock sensors.

Revrun

I haven't tried. I've read the thread and it sure would make it easier if I can find an ecu pinout. I could switch the wires at the ecu or try to bypass.

I've read and researched and I think you are correct that usually it's the wiring to the sensors. I haven't read one confirmation of anything other then wiring. It would make sense that a faulty injector, etc could cause the code.

Btw, I did clean the maf, used sea foam cleaner directly into the intake and a big bottle of lucas fuel cleaner along with multiple bottles of techron, seafoam, and premium fuel.

The hack is my next attempt to fix if I can find out where to cut/splice.

Thanks for the great idea.

Revrun

OK...so the ecu pinout seems to be correct that RKW sent. I mistakenly thought my ecu was behind the glovebox. It is indeed much easier and available behind the driver headlight.

Tom57

Are you going to splice into the known good knock sensor and use it as a "slave" sensor for both banks of cylinders?

The wires at the connectors apparently can fail from excess heat due to their location sandwiched between the engine block and the intake manifold overhead.

Revrun

That is exactly what I did. It was a little gamble, but it seems to have paid off. I simply spliced knock sensor 1 and 2 together. Then I cut the "bad" sensor wire going back to the sensor. No check engine lights. Runs just like it should and as easy as it was to execute, wish I would have done it sooner.

The hardest part for me was disassembling the glove box to get to the abs? module that I thought was the ecu. The ecu couldn't be easier to get to. Folks with the similar GS430 are a little more open to experimenting and trouble shooting in this workaround. All I can say now is so far so good.