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I have done the Hack a week ago, everything perfect since, Rx300 was with p0330 and with shifting/acceleration issues. I just made my user account to thank you for this.
I have done the Hack a week ago, everything perfect since, Rx300 was with p0330 and with shifting/acceleration issues. I just made my user account to thank you for this.
Fair warning and advice to those of you who will do, and have done, this hack:
This is a HACK, and should not be considered a permanent fix. The 1st Gen RX300's appear to be notorious for this issue and a small handful of other issues. If you are going to do this I highly recommend that after doing so you determine how to replace the sensors (or in my case the wiring harnesses). Figure out if you are going to do it, or if you are going to have a shop do the work and prepare for it, because it is my opinion that it is only a matter of time until the other sensor begins throwing the knock code. Just fair warning. (in my case 33,000 miles before the other knock sensor went out)
Also, my advice, if you are going to do this job or have this job done, it only makes sense to also have a full tuneup. Your going to be tearing all the way down to the rear valve cover anyways, so you might as well replace the rear valve cover with the newer updated one, and PCV, to prevent the whole "oil leaking through the PCV" issue, replace your spark plugs, replace all of the gaskets and seals you're going to have access to.. SUPER DUPER worth while if you want this car to last and run really well. It can be a costly or time consuming venture, but I believe $2,000 spent on this car, and knowing its exact condition, is money better spent than on some "new" car that you'll be unfamiliar with and likely will not be nearly as dependable and serviceable.
Fair warning and advice to those of you who will do, and have done, this hack:
This is a HACK, and should not be considered a permanent fix. The 1st Gen RX300's appear to be notorious for this issue and a small handful of other issues. If you are going to do this I highly recommend that after doing so you determine how to replace the sensors (or in my case the wiring harnesses). Figure out if you are going to do it, or if you are going to have a shop do the work and prepare for it, because it is my opinion that it is only a matter of time until the other sensor begins throwing the knock code. Just fair warning. (in my case 33,000 miles before the other knock sensor went out)
Also, my advice, if you are going to do this job or have this job done, it only makes sense to also have a full tuneup. Your going to be tearing all the way down to the rear valve cover anyways, so you might as well replace the rear valve cover with the newer updated one, and PCV, to prevent the whole "oil leaking through the PCV" issue, replace your spark plugs, replace all of the gaskets and seals you're going to have access to.. SUPER DUPER worth while if you want this car to last and run really well. It can be a costly or time consuming venture, but I believe $2,000 spent on this car, and knowing its exact condition, is money better spent than on some "new" car that you'll be unfamiliar with and likely will not be nearly as dependable and serviceable.
If a person had a modest scan tool (i.e. one that let you monitor live data for at least some PIDs) would there be some way to tell from the scan tool whether this hack has been performed on a car you are evaluating? It seems to me that if this hack had been done, then the data from both knock sensors would be in lock step with each other. And I am suspecting (but do not know) that in real life, they would be sending slightly different info at any given moment in time.
I have an Actron CP9580, but have not learned enough about the live monitoring side of it to use it effectively. But if it would let me determine this, it could be useful if I found myself evaluating another RX300.
I suspect that there are some PIDs that should be looked at closely here, but I do not know what they are. I also wonder if access to TechStream Lite would be enough of a tool to determine if this had been done.
My understanding is one would need to remove the glove compartment to determine visually whether this hack had been done.
I did this fix and it is working. Many thanks to Bobster999 and cwsteini.
Previously I would get the P0330 code after a few miles of driving on the Interstate at 70+ mph. Before I did the fix, I tried to measure the output from the two sensors to see if I could determine if the sensor was bad or the engine was acting up.
Prior to cutting the wires, I removed some of the insulation on both sensor wires so I could probe the signal while driving the car. I used the 12V power outlet for ground. Doing some research I found the knock sensor output should be an AC voltage. Using a digital multimeter I was not able to get any AC voltage reading off of either sensor, it was a solid 0.0 V. I did measure a small DC voltage that continuously varied from 30 to 60 mV, but it was the similar for both sensors.
I then cut the wires and did the splice, After the splice, the code so far has not returned after about 300 miles of interstate driving.
Thanks Bobster999 for sharing this fix. I have a 1994 LS400 and 1995 SC400 that had poor performance and excessive exhaust temperature. No codes were being set on either car. I did all the tune-up stuff with no help. I even modified the Ls400 exhaust because it acted like a restrictive exhaust. Searching through the forums for idea's I found this thread. I did the modification and both cars and both are now ok. I think in these cars the knock sensors are over active and retarding the timing when not necessary. In my case both cars run fine running on bank 2 knock sensor only. Do you think it is possible that the knock sensor is picking mechanical noise from the engine as they rack up high mileage. I notice with the RX300 it is usually only one bank that causes problems, what are the odds that that knock sensor always fails first. Thanks again.
Thanks Bobster999 for sharing this fix. I have a 1994 LS400 and 1995 SC400 that had poor performance and excessive exhaust temperature. No codes were being set on either car. I did all the tune-up stuff with no help. I even modified the Ls400 exhaust because it acted like a restrictive exhaust. Searching through the forums for idea's I found this thread. I did the modification and both cars and both are now ok. I think in these cars the knock sensors are over active and retarding the timing when not necessary. In my case both cars run fine running on bank 2 knock sensor only. Do you think it is possible that the knock sensor is picking mechanical noise from the engine as they rack up high mileage. I notice with the RX300 it is usually only one bank that causes problems, what are the odds that that knock sensor always fails first. Thanks again.
I am sorry to intrude, Lexus owners......but I HAD TO respond to Bobster999's thread. Thank You Bobster sooo much. We Toyota owners read You Lexus owners posts and Bobster's and the subsequent posts were awesome. I own two Toyota Siennas, a 2001 and a 2004. Both have the same mz-fe engine as many Lexus' have. Both of my vans had the same code P0333 come up, preventing me from smog passage. Unlike the P0330, which appears to be either a short in the sensor or in the harness, the P0333 is a high voltage reading (the computer sends out a 5 volt reference signal and expects it to be immediately shunted down to a much lower voltage due to the voltage drop from a properly grounded sensor providing a known quantity of resistance thereby causing a reduction in voltage as seen by the computer.) The P0333 is apparently an open circuit in either the knock sensor or the harness. In either case, P0333 is for bank 2. Yes, the dreaded bank 2 was problematic for both of my Siennas. I have a work truck that I drive most often, so my 2001 doesn't get that much use and I am not totally dependent on it...but my wife's 2004 is absolutely necessary for her work. So I thought "if I'm going to monkey around, best to do it with my van which I don't depend on like my wife's" The photos that the other gentleman posted (my apologies to You, I do not remember Your name) were absolutely fantastic for helping me with this hack.
On my van, I have the two white wires coming out of the computer, so I first clipped the one that I thought was probably bank 2, then drove it and the computer immediately threw the code P0330 (which totally conflicts with my theory, but whatever......it's still a bank 2 malfunction detected.) So I then stripped the clipped bank 2 wire from the computer and tied it to the bank one wire (didn't cut bank one wire, just removed insulation and tied #2 wire to #1) Voila!! I then drove only about 20 miles over the course of one evening and one morning and all my readiness monitors reported ready for testing. I then got it smogged.
So then with my wife's van, the wiring was totally redone for the 2004. So I downloaded wiring and connector diagrams and found which wires were for the bank 1 and bank 2 knock sensors (solid red and solid green wires in a totally different connector than with my 2001. I performed the hack, and cleared the codes, and thought "Voila!!" again..........ooops. Drove my wife's van for over 100 miles, repeating the specific Toyota drive patterns, but the readiness monitor for the catalyst would not complete. I am writing this so that if anyone has the same problem, they will know what to do. The tech sheet for the Toyota drive pattern to allow the computer to complete the catalyst test states that "the engine coolant temp must reach 178 degrees farenheit before the test can begin" What it doesn't tell You is that if the engine coolant drops below that 178 degree mark anytime during the catalyst test, the computer will drop out of that test and just seek to perform the test later. I had a bad thermostat that would allow the engine to reach 178 while sitting and idling, but once on the open road (hello scan tool for helping to monitor sensors while driving) the coolant temp would drop down to the 150-160 degree range. Yep, I ended up driving over 100 miles at ridiculously slow speeds (following the Toyota drive pattern instructions) so that the computer could perform a test that it could never complete. I changed the thermostat (thought it would take forever, but it only took 45 min. from start to completely finished), and within 25 min. of driving, all my necessary monitors set to "ready"!!! Got it smogged too. Both vehicles taken care of and smogged in one weekend.
So just a warning to You all who are having trouble getting the catalyst monitor to set so You can smog Your vehicle....make sure Your engine temp is staying up where it needs to, or the monitor will NEVER go to a readiness state.
Thank You again Lexus owners (we corporate Toyota owners can learn from each other) for helping me with my problems. You guys are AWESOME!!
Can someone share the wire size for the black and white wires? I''m try to figure out if I can use the 16-14 disconnect pairs, which are the blue ones (fitting two wires in looks like the two wires will be too big) .
Can someone share the wire size for the black and white wires? I''m try to figure out if I can use the 16-14 disconnect pairs, which are the blue ones (fitting two wires in looks like the two wires will be too big) .
I used Tyco connectors from Home Depot, 18-22 size for the single wire from the good knock sensor and 14/16 size for the pair of wires leading to the ECU. The mating connector housings, although for differing wire sizes, are fully compatible with each other.
Female: Model # CPGI-2-520264-2-10 Internet # 202204294 Store SKU # 280413
Male: Model # CPGI-3-520107-2-10 Internet # 202204292 Store SKU # 280248
11-07-15, 05:02 AM
es300 knock sensor wires
