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Discussion Starter · #1 · (Edited)
So my 2003 Highlander got the dreaded P0325 code. Tore it down and pulled the sensor. I have a data system that can read the output signal from the sensor and when comparing the Bank 1 that was bad with the Bank 2 that is supposedly good it was pretty clear (or thats what I thought at the time) . The good responded with a nice decaying 7.5kHz ring when hit but the bad one was intermittent and had a lot of noise.

I purchased an aftermarket one at O'Reillys and tested that with the same setup. Signal looked good but was at a bit higher frequency. I figured that would not matter. Installed it and took for test drive. P0325 popped up in a few miles.

I can probably pull it in a hour and put it back in 2 hours now when it is fresh in memory but I ham hesitant dumping $450 on a pair of OEM sensors until I am sure the sensor is the issue. I left the dreaded M10x1.25 screw in the back out.

By the way, the trick for that *(@#& screw is a short 14mm socket and Harbor freights PITTSBURGH 1/4 In, 3/8 In. Drive Long Reach Dual Flex Head Ratchet. The 1/4 end on the same ratchet and a 10mm socket does well on the clamp next to the throttle body holding the fuel line. I followed Haynes and left the throttle body in the car.

However. I am not 100% sure a OEM sensor will fix it. The cable was in good shape, the old sensor was bad but I was able to test the new one and it was not dead on in output. I replaced the harness too. Reinstalled the Bank 2 stock sensor.

I'm tempted to make a jumper harness to swap Bank 1 and 2 between the sensor harness and the main harness. Does anyone have an idea on where I can get the mating connector for the harness? Does Toyota sell them? Would a scrap yard cut a connector from an engine?

Below is some measurements I did on them. I figure it can be of use for someone.
Thanks,

Tribologist

2003 Highlander
2010 Sequoia






I think I understand what type of sensor they are. They are similar to what was known as Shock Pulse Sensors for monitoring bearings. Its a Quartz crystal and a mass with vary little damping. They act as a tuning fork at 7200Hz and will start to ring if it is impacted. Kind of make sense :) It makes it easy to interface with a simple cirquit that senses voltage and the voltage will be proportional to the amount of shock energy. One can probably test them by hooking them up to a headphone and tap on them or make a cable so you can hook them to the sound card in the computer at the line input. They should ring like a very high pitch bell when getting an shock.

Here is the output of the good sensor. The right plot is the voltage over time. The left plot is a FFT, it show how much of a signal is at a specific frequency. A pure tone gives a spike like this. Note it is at 7200Hz.

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Here it is zoomed in a bit. You can see the voltage swing. The sensor is actually not outputting a voltage. it is outputting a charge. The voltage is totally depending on what is used to measure with. I'm using a data system that loads the sensor very little.
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Here is the output of the Bank 1 (Bad sensor) You can see its intermittent and noisy but at 7200Hz.
Colorfulness Slope Rectangle Line Font


Here is the O'Reiley "Import Direct" $69 sensor. Clean tone but at higher frequency. About 7640Hz.
Colorfulness Rectangle Slope Plot Font
 

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Discussion Starter · #6 ·
Thanks Hayabusafalcon


That's pretty much the plan, at least for starters. That's why I like to get the mating connector. If I get that I can swap the two and see if the error move to P0330 and I can do the hack without cutting any cables. I have the knock harness side connector from the old knock sensor harness, I need the one on the engine harness. I called a few junk yards and they would not cut a connector out of a 3.0 V6. Those engines are not sitting on the shelf and he rarely get a car with blown engine and the blown engines ends up on the regular scrap yard as scrap metal.. There is a pull place in north end of town that I might go and check. they don't even list what cars they have. Its easy to get to from under the airbox. (to cut that is, not easy to clip loose. I broke it of and zip tied it...)

Tribologist
 

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Discussion Starter · #7 ·
Found this Harness repair manual and the part number of the connector The one on the harness is marked 11268 so it mates with a housing 90980-11269 and use terminals 82998-12440

Housing and terminals is about $35. Going to check at my local Toyota if they have it. With that I will make a breakout harness where I can Supra Hack or swap Bank 1 and 2. Will be fun.. You always learn something. I really appreciate to find information on this forums and I do my best to share back I never been really active on the Toyotanation since My Sequioya and the Highlander just keep running but the Highlander has 238k on it now and the Sequioa need a new transfer case actuator..

Here is the connector information.

https://www.toyota-tech.eu/wire_harness_rm/RM06H0E.pdf

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Connectors can sometimes be found by Toyota part number on Amazon, or
 

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Discussion Starter · #9 ·
Connectors can sometimes be found by Toyota part number on Amazon, or

Thanks, I ordered at my local dealer. Should be here by end of week. It will be interesting to see what the signal look like when driving.
 
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