P0325 Knock Sensor Diagnosis - EricTheCarGuy

[@tahitianflower]

Really like how you post your failures too..makes me feel like youre genuine.

[@J00bles]

As a technician myself, i truly enjoyed this video. It's always great to see how another guy goes about checking for faulty sensors, and i appreciate you keeping all of the "bloopers" of the failed readings within. Its just proof that not everything will work 100% every time! thanks again for another chapter, Eric!

[@thewhiskeysgt]

Thanks Eric. I have a 2001 suby and just had the bad news from mechanic that I have a knock in the engine and it wasn't worth putting money into a car with 200k miles on it. I had the same issue with performance slow to go from a stop. I found your video and the called the mechanic to see if they even tested the sensor. They said yes we did. I asked did you try to put a new one to see if that was the problem. No they said. I went to the parts store and it took me 10 min the change it. And now I am back in gear with my trusted suby. Going for 300k.

[@pamelavance648]

Is suby still on the road to 300,000 😊😊😊

[@UOttawaScotty]

This is one of those pillar OG KZbin channels that is ALWAYS good no matter what, thanks for your hard work Eric !

[@livemeyer]

LOVE that paper trick! Going to use that one for sure!

[@rrbrian222]

Looks like the comment about doing this repair the scanner danner way has been removed. For me, the guy in his garage trying to fix his car, Eric's method of diagnosis is more practical/economical and still goes beyond just "throwing parts" at the problem because he verified the root cause. Excellent video, thank you Eric.

[@dobisayek]

I truly appreciate your visual (video) work, arrows pointing towards the crack, showing pertinent line on your code reader,.....etc. will remember at 12:27 word of the day : "Mental Library", will use it with your permission!

[@douglasmorgan9855]

youtube is awesome it's the perfect tool for the do-it-yourself kind of guy

[@eyesalooking]

Thank you. I am new at this stuff learning from all of you experienced you-tubbers. There are still some older Subarus still on the road, so this information is still valuable in 2022. I will be using this to test a 2001 Subaru Outback with a check engine light. From my research on the internet if you get to 5v unplugged it means your wiring is good all the way back to the ECM.

[@Nwest82]

Thanks again Eric for another great DIY mechanical video. I too am dealing with the p0325 code on my 97 maxima. And having performance issues which I think may part of the problem is the knock sensor, (KS). The first test you tried didn't work because you multimeter can't rang high enough. I just bought a $50 one and its really nice, but even this meter can only range as high as 40M ohms. Thanks for displaying the other way of doing it. You pointed out a little crack in the KS. One thing the FSM doesn't tell you, even though it practical %100 true, is that if there's even a small crack the KS is guaranted bad. Don't know why the FSM doesn't list this as part of the diagnosis procedure. Its the same as the FSM for my 97 Maxima.

[@jassboona8040]

Nate West I have a 97 also , were is it located at

[@jassboona8040]

How can I change it easy ?

[@Da305Alive]

That how a REAL mechanic gets it done. No parts changer here. Great vid Eric!!

[@Roger-pw3zz]

Can't tell you how much I learn watching your videos. You are a natural educator. Nice work all around.

[@darkbyte2005]

this was absolutely fantastic trouble shooting , and Eric your perseverance was impeccable... I learned something as well about knock sensor

[@jschirr]

Way to go the extra mile here. Nice job, and incredibly satisfying seeing this done appropriately.

[@jay7264]

another great video eric. i followed your advice about my hard starting solara and it was the fuel pump for whatever reason the fuel pressure would drop over night which is why the hard starting was only after the car sat for awhile thanks so much

[@rpinarreta]

Common issue with the late 90's EJ25 Subaru engines. My local parts dealers wanted anywhere from $69-$144 for a replacement sensor. After reading Subaru Blogs and found may successful installs of a $14 Ebay replacement part, I thought what the heck. Installed the new sensor cleared the OBDII code P0325 and wow no more engine shaking and no more "check engine light". Since floored at the price via ebay vs traditional parts retailers.The knock sensor is not that complex and cost

[@bigoak7010]

Good to see an honest proper repair rather than a hack to bypass the knock sensor. One fellow published hack on KZbin for a Lexus so that the buyer of the car would not see the check engine light. Thank you! Keep it up. Integrity gets noticed.

[@bikerrealengo]

Erick...thanks for show us your skills in mechanics and the real problems and solutions you found...good job...!!!

[@zee-lusay4087]

Do a quick check on your multi meter. Some have a limit to what they consider "continuity". 0.7 mega ohms is a lot of resistance to consider clear circuit. I myself always try a reading of the actual resistance before I say the circuit is open. It tells me if there is a bad connection or broken connection/wire. Thank you Cape Hatteras NC for teaching me that lesson.

[@pjvenda]

Hi Eric, depending on how your multimeter works, you might want to avoid using the continuity sensor to probe for resistance (as suggested by the manual). My multimeter will beep in the continuity tester mode if there is continuity, which in its terms is having a resistance of less than 25 ohm. In other words, the continuity tester not beeping would not mean the test had failed (according to the manual). Yours might be different and may behave in a different way.

[@mechanacae811]

The stuff in the schematic you were wondering about was the shielding for the knock sensor wire, grounded at the ECU. Without it the EMP from the coil could induce a slight enough current in the sensor wire to trigger a false positive for knock. The funny looking parts are just connectors where the shielding is joined to the other pin.

[@mmuller3233]

Thanks for following up with the test drive & suggested test procedure letter. A very comprehensive and user friendly tutorial from start to end!

[@DJDevon3]

You did everything the manual said to do and you felt defeated... makes me feel bad for the Subaru techs that had to deal with crappy manuals all the time. Ouch. GJ. Looking forward to more like this.

[@Bob-hh2sf]

I have a 2001 Subaru Outback 2.5L My knock sensor was replaced by my mechanic. I tell him my check engine light comes on and goes off intermittently but not all the time. My engine performance is being affected and mileage. Thanks for your video now I’m doing voltage testing on my own. I will probably get the sensor from Subaru parts department at the dealership because I understand these sensors have a specific frequency compared to aftermarket. Like rock auto

[@zxtenn]

Hey Eric, i sometimes use some permatex #2 to hold bolts but your method is neater

[@wmcartpusher04]

Very glad to see you checking the NEW knock sensor for resistance. Good man. ALWAYS CHECK NEW PARTS!!!

[@pro6580]

EricTheCarGuy 1990 na vg30e to vg30dett Frankenstein motor, took about 12 months and allot of blood sweat and money but in the end it is well worth it! thanks again for the free lessons brotha

[@klmartin1962]

Good job of following through. On GM products, I always used a long extension and a small hammer on the block beside the sensor while the vehicle was running. This worked great on them. One thing I wanted to mention, just fyi, most sensors have the same 5vdc reference. You can almost always check any sensor (input) that same way. Great job. I love the videos. Thanks for sharing.

[@letthechipsfly7620]

Outstanding."I want you to understand the diagnostics" ........Best YT bar none. Thanks Eric.

[@alldayandnight09]

the tap test has worked for me on some cars though. its kinda cool to see the data change but it wouldn't be enough to justify a replacement sensor. you should always test the sensor and circuit. great video! Real world diagnosis at its best.

[@JC-mr4rz]

Your reading resistance with the battery hooked up? Hmmm Suburu was very thoughtful to place that sensor in such an accessable place! 🙏

[@qx9r7man]

Hi Eric! Computer power supplies often give 5v and 12v signals that are off (usually low) by half a volt. Chalk it up to losses and inadequate connections. Keep up the good work!

[@Zeppelin6882]

you said that Eric... this is the real world. Thanks for sharing this video.

[@user-px9zd5bg5c]

Thank you very much , there are two things about the sensor that i was confused about and I found the answer , you are the first-rate technician.

[@cbh148]

So glad I watched this. Nissan's factory service manuals says the same thing for testing their knock sensors (which are almost identical to Subaru's), and that's to check for continuity on the sensor itself, and that's just flat-out wrong just like in this video! I'm bypassing my knock sensor with a 1 megaohm 1 watt resistor to never deal with it again since I run 93 octane and have a lot of modifications that can cause sounds that the knock sensor might misinterpret as predetonation.

[@xai1603]

good quality stuff Eric, and as always being modest and an honest guy way to go on both test from this vid and the follow up to retest the factory manual testing method!

[@poraradi1919]

I LOVE ALL YOU VIDEO BECAUSE YOU COVER ALL POSSIBLE EXPLANATIONS FOR THINGS THAT HAPPEN.

[@2cyclemix]

Dude, great job on the video and not giving up and assuming it was fixed.

[@TooSlowTube]

At 8:20 ish, what range was the meter set to? Is it auto ranging? The green lettering doesn't show up on the video, but the display shows 200, over a little square blob. As it reads 0.3, for 0.3 Ohms in your continuity test, it would seem to be set to a 0-200 Ohm range, in which case anything over 200 Ohms would show as out of range. The meter I have with a setting that beeps for continuity only does that on the 200 Ohm range, which makes me think that's what happened there. Also, what does your meter show when you just touch the probes together? Mine shows 0.2 Ohms as a minimum. I own a few digital multimeters, and they all do that.

[@aussiefirestorm]

Very very good video, showing the people what us mechanics sometimes have to go through to figure what is going on or off as the case may be. This is how to do it properly rather than just bolt on parts and hope.

[@SirSeanSean]

I had the same intermittent lag/bog on my 92 Legacy. It turned out to be a bad connection on my air filter housing. Thanks for the replacement video.

[@crickle47]

Working on a 1990 MB 500SL, that has severe timing retardation, and your video helps tons, BECAUSE the knock sensors (2) are underneath the engine mounts, ffs. So, it will be nice to have a confirmation that this is what is causing my driveability problem. Thanks again.

[@phasehalide]

Eric i have been following you and you videos for quite a while now, it looks like you are a great mechanic and do very many things and inform people about so much and i appreciate you and what you are doing very much but you possibly have overlooked something here... The Subaru manual should be correct, What i saw you where checking was continuity witch is measured in ohms NOT Kilo ohms! What you would have to do is turn the dial of you multimeter to the 1000 or 2000 kilo ohm setting and then look for a reading with the plug disconnected as you did and that should give you a correct reading of something close to 700 Kilo ohms. Kilo ohms are in the thousands not hundreds. I hope i make sense, keep up the good work man!!!

[@Perrytraywick]

Paper trick is worth it’s weight in gold! Love it. Will use it.

[@MrSnowmobilefreak]

I'm not going to lie, I thought when you started to talk about smacking on the engine with a hammer I thought you were just being funny. but I gave it some thought, pretty clever!

[@Spencerianism]

Comprehensive to the max, Eric..Kudos! Any other "mechanic" Would say it's shit and call it a day, and that attitude just doesn't hold water in the real world..Excellent job on a proper diagnosis.

[@robertv8851]

That's why it was working and then not working.what scares me can you short the computer acidently back probing Eric,thank you this was very help full

[@rulerpaco]

we keep learning every day.. good work, videos like this saves time and money when looking for a problem. and how to solve it

[@plznotears]

Your service manual was correct, it didn't ask you to test the resistance of the sensor, instead it asked to ensure that there is no short circuit to ground, reading an open circuit tells you that your sensor is not internally short circuited directly to ground, 700kohms is basicly an open circuit in a 12v system Good video's Eric, keep it up!

[@darrinsiberia]

When my transmission shop put in a new transfer case is it possible they shorted this sensor because now I have a p325

[@xanderlander8989]

You sir are correct about the "auto" beeper mode. the range on my meter is 0-100kOhm so anything above that will read as open in auto mode. It would be interesting to test the two sensors in manual mode...

[@richstarbuck4315]

Eric, your video made me realize that the knock sensor has no resistance, until it is activated and that the sensor has to see some vibration from engine to keep the light off. I replaced mine in a 2002 Camry 2.4 and still kept getting the code. I isolated it from the engine and grounded it but still got the code. So I relocated it higher on the head bracket to see and no more code. The engine runs smooth and now my transmission shift to high. Still don't know why the original location kept throwing the code, Thanks

[@jaymiewakefield9189]

Hey Eric, good video. The original factory test would have worked to diagnose the bad sensor as well. You essentially did the same test two different ways. The knock sensor is not grounded through the block like other sensors. The ground comes through the wire from the computer, so when you disconnected the sensor, it was no longer grounded. When the service manual stated to test the resistance to ground, it wanted you to test the resistance through the sensor itself. You would use one prong for negative and the other for positive and measure the resistance through the sensor. I suspect, based on your voltage test, that the resistance would have been very high and proved the sensor to be bad. The voltage drop test is more comprehensive, but also slightly more time consuming. You could start with the resistance test and if that proved the sensor to be bad you would know to replace the sensor. If the resistance test was inconclusive you could move on to the voltage test and get more answers.

[@ronparsons3496]

After working on Subarus for a few years...when using the manuals look for the updates. Until 2006 the manuals were in book form, after that they were on the computer. In the books the updates were sent desperately. And you had to check the updates. sorry you had so much trouble.

[@MyBrilliantChannel]

Great video Eric, nice to see you found the evidence in the end! It gives peace of mind when you know that the part you replaced was the culprit without just replacing it and hoping the problem goes away.

[@armandobenabides3693]

This helped so much! I KNEW something was funny with that manual test procedure! Thank you!

[@pro6580]

EricTheCarGuy its funny that "in essence" reasson you made this video ( to teach people the mindset of learning to trouble shoot items) is something you actually had to you yourself in this video when im sure you figures you were just doing another quick everyday test on a knock sensor circut, simple enough lol.. life man its awesome how it can keep on our toes, keeps things interesting. well enough babble thanks for making the video ive learned a few different test methods from you which helped me fix my TTz32. thanks man keep doing what your doing!!

[@wkl747]

good honest, detail oriented mechanic; also good illustrator

[@ashk0102]

Hello Sir, I am your student and always trying to learn some thing from you and i am thankful for that. Most of your videos you teach us are based on old models while i am dealing with most of new model cars so please Sir try to teach us on some new models too. Thanks best regards.

[@miker.5495]

That little piece of wisdom made my day. Thanks Eric!

[@Knightfamily102]

Eric, that was really funny when you were in the car. Made me chuckle well done

[@makailarose1310]

Eric THANK YOU for this video. I have a question please. I am having this P0325 on my Honda Accord 03. I have replaced the knock sensor twice, thinking it was faulty, however, my engine has no knock. At this point, I have ordered a Voltmeter and will be testing the knock sensor as seen in your video here, but also testing the pins for damage and wiring. The only symptom my car has is the code along with weaker engine performance. No knock, no gas guzzling, just hard to go up hills and accelerate. Do you think it’s probably the computer, so the pins? I hope this makes sense. Thank you

[@chafflube]

Great video and thanks for the paper in the socket wrench tip. I will definitely use that in future. There is nothing more frustrating than dropping bolts into places you cannot reach them. Keep up the good work. Your videos are fantastic, Eric!

[@myadler]

Eric, I can not believe you didn't rip apart the bad sensor. That is usually where I learn the most, how a knock sensor works and, when they break, why.

[@vicus1361]

Thank you so much!!!! An amazing video!!!! It is interesting to know if there isn't another problem. I have the same BS on my 99 subaru forester and I want to know if it is "OK" simply replace the Knock Sensor.

[@arsonist63086]

this video help out a lot thanks man and i know what you mean about what the service manual says one thing a real life says onther , but like the fact that your curiosity didnt let the fact go that th new knock s. was coming out bad with the service manual test

[@392_brooklyn2]

Great video dude and very hopeful I have the same problem on my srt8 charger they just change my crankshaft damper and my antifreeze coolant and the nose is still going. well the great thing about this that my car is under the warranty dodge just returned my car today and I'm returning it back tomorrow I'm going to tell them specifically to change ticking sensor hopefully that's the problem. Once again 👍👍on the video. Thank you

[@rockofages-cs3fq]

Good tip thanks Erick i have a 2000 altima and it runs smooth but on the idol is rough n sometimes a little Stallish when i start from a stop engine light is on to i think thats it maybe.

[@muhindojehoiadapatience4455]

Thanks Eric. This was helpful. Can the same procedure be done on a Toyota vitz ? It has the same problem

[@kls04phx]

This is a great video. Im having an issue with a Lexus, now I have a good place to start. Thanks a lot for this video. You rock!

[@zeidar]

Nice video, things don't always work out well even for professional mechanics, glad the issue got resolved though.

[@gypsyspirit8472]

Great video! Very informative. I just had my maf changed. My codes went from 10 to now 3. The knock sensor is showing up. I'm about to go and try to locate it. I have a i30t infiniti 1997. I hope it's not dificult to get to. This lady likes to handle all she can on her own first. I will return to let you know how it went. Sista C

[@thejuice7020]

Gypsy Spirit how did it go?

[@Rustbox306]

Great video! I love going all the way to the bottom of things like you did there.

[@greygoosealky]

I believe there are two sensors and you have to remove the intake manifold to get to them. Also I would replace the short knock harness they get corrosion in them sometimes.

[@philmoley4418]

great guy our eric

[@ddmd80]

ETCG as a 97 Legacy owner myself I really appreciate this video thanks for taking the time to video the entire process and following up with a good repair confirmation. Your KZbin channel is great!

[@DanteChi]

I'm wondering how relevant the testing instructions Eric received back are for a Subaru in particular or could those same tests and instructions apply for my '04 Honda Element? I've had a PO325 check engine light for months now. Originally the check engine light was intermittent but over the last few months it's held steady. I'm not experiencing any "real" performance issues or hearing any "engine noises" so I've hesitated to conclude it's the Knock Sensor itself. This video has been really helpful. Thank you.

[@clayhunt1284]

Thank U for a real life diagnosis... I just did this the other day .. and I wish I saw this first

[@botella7771]

thank you for your honesty, great video. i enjoy it

[@colinadams495]

I just did this for the first time on an 01 Legacy and it was easy. And to think at first I was nervous about it

[@RandallFlaggNY]

One of the best videos I've ever seen on KZbin.

[@granlyfernandez4414]

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[@granlyfernandez4414]

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[@gvvq-pi5ml]

Hi Eric i'm sure this is an old video, but i am informed that if you have the sensor out for instance and you put an AC voltmeter on it, on low setting and tap the sensor, or lay a hammer on it and tap the hammer it should generate about 2 to 3 volts....from Fred in UK.

[@moderndino]

Mastergx1's suggestion is valid..... I'm an engineer and a mechanic. You could try an analog meter (the one with a needle), or do what I'm able to do. I use an oscilloscope to see the output of the suspect knock sensor. It is a crystal (piezo) device that generates an electrical output when stressed mechanically. Some phono and microphone pickups use this tech. A crystal pickup is high resistance.... 700K ohms is high and typical. By connecting the scope probe to the sensor, you only need to tap it lightly to see the scope trace dance in response. This way you are sure of the initial fault, and the value of your repair. I've done this on the EJ22 engine.

[@rogerlarratt9651]

Thanks Eric. I have been looking for this exact information

[@gilbertojim1263]

Thanks a lot great video you’re the only one Des Plaines clearly what to do

[@SuperTurboDiesel2]

LOL, I thought the exact same thing! In Eric's defense, I'll bet good money that the old sensor was still bad though. Subarus are known for defective knock sensors. Eric's test procedure and video on this one sure wasn't very good, but he got the job done. I would have sandpapered the engine block up a little where the sensor mounts, to ensure a good ground and used a little dielectric grease. I would have tested the NEW sensor's ohms readings and compared it to the old one before installing it.

[@tomcraigmatthews9300]

Thanks for real world problem solving.

[@MrGuitarRadio]

I am not familiar with that brand of DMM (digital multimeter) I also thought that te meter was set on continuity check and wouldn't be albe to measure higer resistance such as 700 kilo Ohms on that setting. (Can't see the green legends on the video). The second procedure IS more conclusive. Thanks for always going the extra mile and include it in the video instead of just leaving it at the first attempt.

[@estrelladelnorte1308]

hey eric some meters cant read high resistance , i found that the hard way myself, it could be helpful to make sure the meter is capable to read it before even start. nice video!!!

[@muadeeb]

Yes, you have a $400 (list) meter, ETCG has a much less expensive meter that was re badged as a Snap On. Continuity can usually test up to 200 Ohm.

[@nextlvl7344]

I think when you are grounding the signal in the end it wasn’t a good connection. Can you do that again and confirm? I like your work! You’re my favourite.

[@Autofixgarage-ng]

Eric u re a genius of high standard. Pls try to make a video on knock sensor live data.

[@paulwright3261]

Great video Eric. Very thorough and informative.!

[@phasehalide]

Just saw your the RE: Video you have already covered it, Good job!

[@dreamer2355]

I would also recommend torquing down the KS bolt to factory specifications :)

[@xide3]

That paper trick you showed us is genius i will remember that!

[@nasboost1031]

Even tho the hammer trick didn't work i appreciate the creative troubleshooting ideas.

[@dustergirl107]

Thank-you. I changed it. The check engine light is off and it doesn't cut out going up a hill now. I was a B**** to get to, but it's done.

[@happydave5806]

Just wanted to say I really liked the way u handled this in the video! Very cool how u showed everything and didn't just edit out any mistakes! I really got a good laugh at the beginning of the video when u couldn't get the car to act up lol...never fails!😄 Even with a couple miscues this vid was very helpful though! Thanks 👍

[@cindynapoli7530]

Glad it happened to you it was quite funny.. Mine does that as soon as I go to the mechanic

[@marianatequiero28]

Thax Eric been drivin with the same check engine light for to long