Anyway to bypass the knock sensor
#81
Just checking because I have a pretty good amount of experience with knock sensors on Nissan 240sx's, and it sounds like they're basically the same as these Toyota knock sensors -- not only in their construction and theory...
On those early 90's Nissans, the majority of the knock sensors have bit the dust. It's always the knock sensor, never the wiring harness or knock sensor subharness. And it's not uncommon for people to just delete the knock sensor...
...and I drift the car regularly and it's never had less than stellar compression numbers.
On those early 90's Nissans, the majority of the knock sensors have bit the dust. It's always the knock sensor, never the wiring harness or knock sensor subharness. And it's not uncommon for people to just delete the knock sensor...
...and I drift the car regularly and it's never had less than stellar compression numbers.
Next, Toyota knock sensors last forever...UNTIL PROVEN OTHERWISE!!!
I'm still running one that's 28 years old, and another that's 26. No issues whatsoever with either one. Or the spare I've got(which I don't know how old it is). And I've never heard of one EVER failing(due to age/wear or any other reason for that matter). I'll bet I can make any supposedly "dead" one work by cleaning the pin and establishing a good electrical connection. Lack of which is the only way one would ever appear not to work. Old-school solid-state electronics...will live WAY longer than you will.
Last edited by MudHippy; 01-10-2016 at 08:49 AM.
#82
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... And it's not uncommon for people to just delete the knock sensor by wiring in a resistor that is of the particular resistance value needed to satisfy the ECU from throwing the knock sensor circuit error code. On my SR20DET, for example, a 1 Mohm (aka 1 Mega-ohm, aka 1 million ohms, aka 1,000,000 ohms) resistor does the trick. ...
It would be the same as trying to eliminate a code 25 or 26 by replacing the O2 sensor with a resistor. Both the knock sensor and the O2 sensor generate a voltage, and the ECU is adjusting something (timing and mixture, respectively) constantly looking for the signal to switch back and forth. Even if the ECU monitored the resistance of the sensors (it doesn't), it would still find that the voltage (specifically, the change of the voltage) was missing. That's what throws the code.
I don't have MudHippy's manifest charm, but he is correct (about the knock sensor; I don't know what cbh148 knows or doesn't know.) Not only is there no reason to delete the knock sensor, there just isn't any way to get the truck to run correctly without it. You're trying to make it set timing blind. It would be like replacing your windshield with a piece of plywood that has a picture of your driveway on the inside. Even if you didn't notice that change at first, you'd run off the road pretty quickly.
#83
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There's no sensible reason to EVER bypass/delete the KS. You obviously don't know how it works. BTW, compression has nothing to do with it. Proving you don't have a clue what you're talking about.
Next, Toyota knock sensors last forever...UNTIL PROVEN OTHERWISE!!!
I'm still running one that's 28 years old, and another that's 26. No issues whatsoever with either one. Or the spare I've got(which I don't know how old it is). And I've never heard of one EVER failing(due to age/wear or any other reason for that matter). I'll bet I can make any supposedly "dead" one work by cleaning the pin and establishing a good electrical connection. Lack of which is the only way one would ever appear not to work. Old-school solid-state electronics...will live WAY longer than you will.
Next, Toyota knock sensors last forever...UNTIL PROVEN OTHERWISE!!!
I'm still running one that's 28 years old, and another that's 26. No issues whatsoever with either one. Or the spare I've got(which I don't know how old it is). And I've never heard of one EVER failing(due to age/wear or any other reason for that matter). I'll bet I can make any supposedly "dead" one work by cleaning the pin and establishing a good electrical connection. Lack of which is the only way one would ever appear not to work. Old-school solid-state electronics...will live WAY longer than you will.
Compression is a relevant metric for this topic because, if removing the knock sensor was going to have consequences on my engine, then that would be because the engine would encounter predetonation and not detect it with the knock sensor, therefor no timing would be pulled or fuel added to combat the condition, so then either immediately or shortly thereafter it would melt pistons, destroy ringlands, etc. etc., which would make it blow up entirely or at least begin to burn oil and return non-perfect compression numbers, which it doesn't do because like I said the compression is perfect. And the car gets put through its paces, so it's by no means like I'm babying it and not giving it the chance to break things lol
[YOUTUBE]8KN7Yh6CuRY[/YOUTUBE]
For reference, that's me in the red 240sx with the bike rack. This is only the most recent thrashing the engine has seen.
Now for clarity, I'm not saying that this necessarily works with the Toyotas because this is new territory for me. You'll notice this post is not edited because I wanted to make sure I got this claim in here before anybody tried to make it out like I said otherwise, then went back and edited my post to add it in there. It's just that these engines were from the same era and from similar manufacturers, so there's reason to believe they might operate in a similar fashion to help understand the system better overall. The reason some elect to eliminate the knock sensor is because, even when "working" properly, they can have issues of returning erratic, erroneous signal and causing the ECU to act as if there's knock that it needs to fight, so power is lost for no reason. This is only one of the ways they can screw up, and it's not even a circuit fault which is what actually throws the code. Lots of variables here.
#84
#85
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Arguing on the Internet is like the special Olympics.
Even if you win, you're still retarded.
Today I plan to try some other things. I found a brass adapter in the plumbing section of the hardware store that the sensor will screw into, that will also thread into the bolt holes for the lift hook.
Can anyone tell me whether or not that might send a sufficient signal to the computer to turn off the code?
I still only have the new aftermarket sensors, one for an s10 (not likely to work, so I'm not likely to try it anymore ), and a cheapo aftermarket one, and of course, the original one buried under the intake, which I hope to not see again until I know I'm getting a signal to the computer.
I may try to find another used one today, or try another cheapo aftermarket one, or both before I spend the almost $300 for a new OEM one, or the $150 for a BWD one from the McParts place up the street.
I figure I'll keep trying the cheaper options, since a few here are adamant that these sensors never fail.
Cbh148, I'm not sure what your ecu is getting a signal from, but knock sensors generate their own electricity via the phenomenon of piezoelectric materials. The ecu does not send any electronic signal to the sensor, only reads what the sensor sends to it, and it is pretty specific about frequency and voltage. Find me a resistor that does this, and I'll tell you that you have a faulty resistor in your hand.
Having said that, however, I will acknowledge that on my early (renix) jeep Cherokees, the knock sensors could be unplugged, and the thing ran just fine. I even swapped in a newer engine and just clipped the wires for the knock sensor on one of them, and never missed it.
You have no idea how much I wish Toyotas were the same. If there was a way to bypass the knock sensor and have the truck run well again, I'd do it in a heartbeat, regardless of potential damage to the engine. I would be happy to adjust the distributor back a bit and run high octane fuel to avoid pinging, it if we're an option.
I have yet to hear from anyone who has experienced engine damage that could be blamed on a lazy solution to their code 52 problem, only people who say it will happen, who haven't seen it happen either.
But that's another topic.
I just want my power back.
Even if you win, you're still retarded.
Today I plan to try some other things. I found a brass adapter in the plumbing section of the hardware store that the sensor will screw into, that will also thread into the bolt holes for the lift hook.
Can anyone tell me whether or not that might send a sufficient signal to the computer to turn off the code?
I still only have the new aftermarket sensors, one for an s10 (not likely to work, so I'm not likely to try it anymore ), and a cheapo aftermarket one, and of course, the original one buried under the intake, which I hope to not see again until I know I'm getting a signal to the computer.
I may try to find another used one today, or try another cheapo aftermarket one, or both before I spend the almost $300 for a new OEM one, or the $150 for a BWD one from the McParts place up the street.
I figure I'll keep trying the cheaper options, since a few here are adamant that these sensors never fail.
Cbh148, I'm not sure what your ecu is getting a signal from, but knock sensors generate their own electricity via the phenomenon of piezoelectric materials. The ecu does not send any electronic signal to the sensor, only reads what the sensor sends to it, and it is pretty specific about frequency and voltage. Find me a resistor that does this, and I'll tell you that you have a faulty resistor in your hand.
Having said that, however, I will acknowledge that on my early (renix) jeep Cherokees, the knock sensors could be unplugged, and the thing ran just fine. I even swapped in a newer engine and just clipped the wires for the knock sensor on one of them, and never missed it.
You have no idea how much I wish Toyotas were the same. If there was a way to bypass the knock sensor and have the truck run well again, I'd do it in a heartbeat, regardless of potential damage to the engine. I would be happy to adjust the distributor back a bit and run high octane fuel to avoid pinging, it if we're an option.
I have yet to hear from anyone who has experienced engine damage that could be blamed on a lazy solution to their code 52 problem, only people who say it will happen, who haven't seen it happen either.
But that's another topic.
I just want my power back.
Last edited by thechief86; 01-11-2016 at 03:42 AM.
#86
Registered User
Seriously Mr. Mud, you're getting way too upset over the internet. Generating that much ill will can't be healthy.
Anyways, if you don't believe me that many knock sensors may be replaced by a resistor without the ECU throwing a code, just google it. It's real.
I think you're mistaken in how the knock sensor works -- you seem to think that the sensor produces a voltage that travels to the ECU which you must think is not outputting any voltage to the signal wire, so you're thinking the ECU is just sitting there passively listening to the voltage signals generated by the knock sensor, so this is why the idea of adding a resistor in place of the knock sensor must seem like it fundamentally can't work -- because a resistor and a voltage source are just fundamentally different things, so there's no way one could substitute for the other. . . but that's not how it works.
Yes, the piezoelectric material in a knock sensor creates a tiny charge/voltage purely from the stress/vibrations it's subjected to, but the way that's implemented here is with the ECU sending 5 volts or so to the knock sensor, and then the ECU is monitoring the voltage drop on that output line circuit (ie, looping back to the ECU through the block/ground). This is why unplugging the sensor causes the code to occur -- because it's designed where what the ECU sees when "all is well, no knock" is a different reading than "knock sensor unplugged". Cause if it was purely that the computer sees voltage from the knock sensor when there's knock, and no voltage across the line when there's no knock, then it would never know the difference if the sensor was just left unplugged and therefor wouldn't be able to throw a code, so you know that's not the case.
This also explains why many FSM's will specify a resistance that the knock sensor ought to have if you probe the ground side and the wire terminal of the knock sensor with a multimeter. That's not to say that the resistance listed there in the FSM is the resistance that you would need to use in making a knock sensor bypass.
Anyways, if you don't believe me that many knock sensors may be replaced by a resistor without the ECU throwing a code, just google it. It's real.
I think you're mistaken in how the knock sensor works -- you seem to think that the sensor produces a voltage that travels to the ECU which you must think is not outputting any voltage to the signal wire, so you're thinking the ECU is just sitting there passively listening to the voltage signals generated by the knock sensor, so this is why the idea of adding a resistor in place of the knock sensor must seem like it fundamentally can't work -- because a resistor and a voltage source are just fundamentally different things, so there's no way one could substitute for the other. . . but that's not how it works.
Yes, the piezoelectric material in a knock sensor creates a tiny charge/voltage purely from the stress/vibrations it's subjected to, but the way that's implemented here is with the ECU sending 5 volts or so to the knock sensor, and then the ECU is monitoring the voltage drop on that output line circuit (ie, looping back to the ECU through the block/ground). This is why unplugging the sensor causes the code to occur -- because it's designed where what the ECU sees when "all is well, no knock" is a different reading than "knock sensor unplugged". Cause if it was purely that the computer sees voltage from the knock sensor when there's knock, and no voltage across the line when there's no knock, then it would never know the difference if the sensor was just left unplugged and therefor wouldn't be able to throw a code, so you know that's not the case.
This also explains why many FSM's will specify a resistance that the knock sensor ought to have if you probe the ground side and the wire terminal of the knock sensor with a multimeter. That's not to say that the resistance listed there in the FSM is the resistance that you would need to use in making a knock sensor bypass.
#87
Registered User
Could the code 52 possibly have anything to do with the distributor? My CEL stayed off between my head gasket repair and the distributor failing, and the car ran great for a couple of days, but then the distributor pickup failed (car shut off as soon as it would get warm, then run fine once cooled down, and had no CEL), and I replaced the distributor with a used one. Ever since then, I've had the code 52.
#88
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??!! Now that's a quote to save. If you can find it by googling it, it must be real.
But not Toyota FSMs.
Some knock sensors have a very large internal resistance to ground to provide the ground return when the ECU uses a very high impedance input amplifier. But the resistance has nothing to do with the signal. Or the missing-sensor code.
I know it's not the same as finding something on google, but these Toyota publications explain how knock sensors work:
http://www.cygnusx1.net/Media/Supra/...taTech/h38.pdf
http://www.cygnusx1.net/Media/Supra/...taTech/h40.pdf
...
This also explains why many FSM's will specify a resistance that the knock sensor ought to have if you probe the ground side and the wire terminal of the knock sensor with a multimeter. That's not to say that the resistance listed there in the FSM is the resistance that you would need to use in making a knock sensor bypass.
This also explains why many FSM's will specify a resistance that the knock sensor ought to have if you probe the ground side and the wire terminal of the knock sensor with a multimeter. That's not to say that the resistance listed there in the FSM is the resistance that you would need to use in making a knock sensor bypass.
Some knock sensors have a very large internal resistance to ground to provide the ground return when the ECU uses a very high impedance input amplifier. But the resistance has nothing to do with the signal. Or the missing-sensor code.
I know it's not the same as finding something on google, but these Toyota publications explain how knock sensors work:
http://www.cygnusx1.net/Media/Supra/...taTech/h38.pdf
http://www.cygnusx1.net/Media/Supra/...taTech/h40.pdf
#89
I've read all 5 pages of of comments for this knock sensor problem and there is a lot of good information. I've replaced the knock sensor and pig tail and still get a 52 code. Starts and runs great until light comes on, then runs like crap. I live in nor-cal in the central valley and would appreciate any advice or guidance on getting my truck back on the road. thanx
#90
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I had to buy the sensor from the dealer before I got one that worked.
I finally got the code to go off with the new sensor threaded into the hole in the head for the engine hook.
Once I got that, I installed it where it goes, under the intake because I was getting some slight pinging, which I know will eventually damage pistons.
I finally got the code to go off with the new sensor threaded into the hole in the head for the engine hook.
Once I got that, I installed it where it goes, under the intake because I was getting some slight pinging, which I know will eventually damage pistons.
#91
I'm working on a new-to-me 94 runner 3vze and have been battling this code since I un-hotwired it. They somehow had the efi system bypassed and it wasn't throwing any codes when I bought it. Gotta love craigslist cars.
I grabbed some rg58 coax(suggested here)and wired it into the ecu (pinout here). Cleared the ecu and 52 came right back.
So I went to o'reillys and grabbed a 4-banger s10 knock sensor as suggested in this thread. I drilled and tapped a piece of metal to 1/4" npt and mounted it to a hole in the side of the block, right above the rear driver-side spark plug.
It actually worked. I've driven it about 20 miles so far.. It's way smoother and sounds much better.
I will be replacing replacing the OE sensor and pigtail at some point, but I just did the water bypass hose and timing belt. I'm not feeling like tearing it all back apart just yet.
I grabbed some rg58 coax(suggested here)and wired it into the ecu (pinout here). Cleared the ecu and 52 came right back.
So I went to o'reillys and grabbed a 4-banger s10 knock sensor as suggested in this thread. I drilled and tapped a piece of metal to 1/4" npt and mounted it to a hole in the side of the block, right above the rear driver-side spark plug.
It actually worked. I've driven it about 20 miles so far.. It's way smoother and sounds much better.
I will be replacing replacing the OE sensor and pigtail at some point, but I just did the water bypass hose and timing belt. I'm not feeling like tearing it all back apart just yet.
#92
don't bypass the knock sensor...
especially if your truck is modified. even if it isn't, don't.
it's usually just the wire, which you can replace with some rg-58 sheilded coax cable, and probably never have to worry about it again.
when code 52 is registered in the ECU, the timing will be retarded, and the fuel trim will increase (rich) in an effort to prevent detonation/pre-ignition.
bypassing that feature wouldn't be smart, to say the least...
-shaeff
especially if your truck is modified. even if it isn't, don't.
it's usually just the wire, which you can replace with some rg-58 sheilded coax cable, and probably never have to worry about it again.
when code 52 is registered in the ECU, the timing will be retarded, and the fuel trim will increase (rich) in an effort to prevent detonation/pre-ignition.
bypassing that feature wouldn't be smart, to say the least...
-shaeff
#93
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93 4Runner V6 knock sensor repair success!
My 1993 3.0 V6 4runner 4x4 automatic! I successfully relocated my knock sensor to the position on the left side ,driverside, to the lift hook BUT, what happened was it didn't work the first time and discovered the brown wire on the main harness side, that went into the clip, was damaged and hanging on by a couple wire strands. I bought a new knock sensor pigtail from Toyota for $22, repaired the existing main harness clip damage,clipped the new pigtail in but the black single wire was a little shy in length to the new sensor location, so I soldered an extension,about 5 inches of same gauge wire, and attached the round male clip suggested down below from Ebay. I clipped in the new pigtail to the harness and attached the 97 chevy S-10 4 banger knock sensor. I had detached the battery earlier to wash out the code 52 and work on the vehicle. Started it up And it worked like a charm! No code, and smooth running engine! I did not have to attach a ground cable! I repeat, I did not use a ground! I was curious about Toyotas new pigtail wire for their sensor and I took all the tape off and found that the black wires outside grounding braid was attached to the brown wires outside grounding braid and the brown wire was soldered to its own grounding braid and taped up ending the brown wires course! The Black wire with a blue encasement, with braided ground inside it , that lead to the sensor connection end, had about 4 inches of nothing but Black wire going to the clip sensor connection and the blue thicker encasement with the braided wire ended 4 inches shy and its braided ground wire folded back unto itself about 1/2 inch with the black wire exposed leading to the sensor clip all by itself! So the black wire is the sensor wire and the brown wire is the ground that goes nowhere, weird but I have come to the conclusion that the brown wire is already grounded within the harness wire setup itself! Good luck! Toyota pigtail wire harness to the knock sensor is part number 82219-35010 "wire, sensor" and this is the round connector you will use on the 97 Chevy S-10 4 cyl knock sensor...
#94
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code 52 bypass
Just wanted to add to this, I tried the knock sensor relocation "trick" did not work for me. 3vze. I tried the factory sensor and the chevy s10 sensor like the one the guy on You tube claims works. nada.
Only after putting the factory sensor and new pig tail back in its original location did my CEL light go out.. Just my 2 cents. pita.
Only after putting the factory sensor and new pig tail back in its original location did my CEL light go out.. Just my 2 cents. pita.
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