Knock Sensors Problem
#46
I removed the plug from the ecm and then unpluged the other end meaning the knock sensors wire.. tested continuity and nothing...several times just to make sure and nothing no reading at all...( I tested the continuity between the ecm plug and the knock sensor plug )
tested the ecm to ground and the reading in both pins were 16.25
When you measured 16.25, Is that ohms, K ohms, or Meg ohms? It is very important which symbol followed the number. 1 ohm or less is a good reading for a wire, 1 Meg indicates that there really is not much left of the wire. Continuity means a very low resistance, (typically less than 1 ohm), open means very high numbers (followed by a MEG).
The docs that I posted were exact prints from a reprint of the factory manuals. All I did was convert the format, and then split the file so that I could upload. It has good information,
If you like, and think that it might help you, I can send you a file that will explain how to ohm out a wire. I believe that it might help you. And don't be discouraged, we all started out knowing very little about these types of things. There are a lot of people here that are willing to help, but it will take a little while.
From what you have written, it sounds like your problem is wiring.
tested the ecm to ground and the reading in both pins were 16.25
When you measured 16.25, Is that ohms, K ohms, or Meg ohms? It is very important which symbol followed the number. 1 ohm or less is a good reading for a wire, 1 Meg indicates that there really is not much left of the wire. Continuity means a very low resistance, (typically less than 1 ohm), open means very high numbers (followed by a MEG).
The docs that I posted were exact prints from a reprint of the factory manuals. All I did was convert the format, and then split the file so that I could upload. It has good information,
If you like, and think that it might help you, I can send you a file that will explain how to ohm out a wire. I believe that it might help you. And don't be discouraged, we all started out knowing very little about these types of things. There are a lot of people here that are willing to help, but it will take a little while.
From what you have written, it sounds like your problem is wiring.
#47
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well you are rigth I may be doing it wrong, my english is not enough to describe what I want and I have to improvise..
my voltmeter has a continuity feature but I do not use it
to test continuity I use 20k
yesterday that was the setting I used to test continuity from one end to the other
and I used the same setting to test to ground the ecm 16.25 each pin (used 20k setting) guess would be 16.25 k ohms right?
let me try to explain (in my poor english) where I tested for continuity, the ecm I think is very clear, but the sensor wires I think is not very clear where I checked
well I revomed the plug from the ecm(the one the file shows) then I unplugged the plug that connects with the knock sensor wire...the knock sensors has a wire right (the one I bought and installed) that wire goes out and then it connects with a plug...well that's where I unplug them and conected one end of my voltmeter to one of the little holes (it has four) and the other end to the ecm plug,of course I looked carefully the rigth holes to check (the second hole up and down from left to right just like the picture on the file shows) I used 20k on my voltmeter
my voltmeter has a continuity feature but I do not use it
to test continuity I use 20k
yesterday that was the setting I used to test continuity from one end to the other
and I used the same setting to test to ground the ecm 16.25 each pin (used 20k setting) guess would be 16.25 k ohms right?
let me try to explain (in my poor english) where I tested for continuity, the ecm I think is very clear, but the sensor wires I think is not very clear where I checked
well I revomed the plug from the ecm(the one the file shows) then I unplugged the plug that connects with the knock sensor wire...the knock sensors has a wire right (the one I bought and installed) that wire goes out and then it connects with a plug...well that's where I unplug them and conected one end of my voltmeter to one of the little holes (it has four) and the other end to the ecm plug,of course I looked carefully the rigth holes to check (the second hole up and down from left to right just like the picture on the file shows) I used 20k on my voltmeter
Last edited by sparks11; 04-21-09 at 09:58 AM.
#48
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did you try different ohm ranges on your multimeter, such as 200 or 2K , etc?'
at this point, it's getting hairy. if you showed us literally with a video of what you did , it could help, but basically, if you can find a live person around you that could check what you were doing as far as following the FSM procedure for checking the knock sensor, then that would be BEST. but let's assume maybe you have just set you multimeter up wrong..... if we are to continue helping you on here
at this point, it's getting hairy. if you showed us literally with a video of what you did , it could help, but basically, if you can find a live person around you that could check what you were doing as far as following the FSM procedure for checking the knock sensor, then that would be BEST. but let's assume maybe you have just set you multimeter up wrong..... if we are to continue helping you on here
#49
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guys first of all I really aprecciate your help.. and I have learned a lot since all of you have been telling me what to do, and yes I think I'm using wrong the voltmeter..live person would be really hard, all my friends and people around me
hardly get interested on this mechanic matters I know how to do a lot stuff on cars but getting a diagnostic is out of my league and idiom is getting on the way
I know the frustation of you and I apologize for that, sorry for the inconveniences
hardly get interested on this mechanic matters I know how to do a lot stuff on cars but getting a diagnostic is out of my league and idiom is getting on the way
I know the frustation of you and I apologize for that, sorry for the inconveniences
#50
I sent you a file that may help you to understand some of the basics on using a dvm. Have you given the harness a good visual inspection? Over the years, the clips that hold the harness in place get brittle, crack and break. Also sometimes people do not re-attach the harness clips after they have worked in the engine compartment. The end result is that the harness will rest on metal parts , and sometimes wear thru the insulation.
If you have not allready looked at the harness, closely inspect it. If it appears to be just laying on a bracket,, engine part,, or anything else, gently lift it up and inspect anyplace it might have made contact.
You could have bad sensors, or bad ECM, (unlikely), or a wiring problem (most likely). Be patient, and keep at it.
If you have not allready looked at the harness, closely inspect it. If it appears to be just laying on a bracket,, engine part,, or anything else, gently lift it up and inspect anyplace it might have made contact.
You could have bad sensors, or bad ECM, (unlikely), or a wiring problem (most likely). Be patient, and keep at it.
#52
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got the files thanks!! and yes knock sensors were properly tightened..hey but remember that I most likely used the voltmeter in the wrong way...then it could mean I checked the wrong way the sensors too! I'm including a picture of the voltmeter I have..you guys are experts on this and can advise what setting I can use to test sensors and wires..
harness look ok no damage and all are well taped
damn! poor pictures but on the ohms section I have 2000k,200k,20k,2000,200
volts section I have 1000,200,20,2000m,200m
then I have another volts section but this has this letter V~ and I have 750,200
then have another section letter A and has 200u,2000u,20m,200m
I want to test the ecm again.. and the wires too, what settings should I use to do that?
hope you understand all this
thanks!
harness look ok no damage and all are well taped
damn! poor pictures but on the ohms section I have 2000k,200k,20k,2000,200
volts section I have 1000,200,20,2000m,200m
then I have another volts section but this has this letter V~ and I have 750,200
then have another section letter A and has 200u,2000u,20m,200m
I want to test the ecm again.. and the wires too, what settings should I use to do that?
hope you understand all this
thanks!
Last edited by sparks11; 04-22-09 at 06:51 PM.
#53
To check continuity, use 200 ohm. Check the meter before you start buy touching the two leads together, you should typically see 1 ~ 2 ohms. You want to see the same readiing when you measure from one end of the wire, to the other.
When disconnect both ends of the harness, and measure the wire to ground, you want to use a higher range, (such at 200k),
When disconnect both ends of the harness, and measure the wire to ground, you want to use a higher range, (such at 200k),
#54
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ok here's a silly post...I have this knock sensor with me right now (one of the many I got at the junk yard) and I'm checking it.. I set my voltmeter at
20k and the reading is 0.67
then I changed the setting at 2000k and reads 031
then I changed it to 200k and read 21.8
changed it to 2000 ohms and reads 547
changed it to 200 ohms and reads nothing no reading....
which of these reading is the one you take? is that a good sensor? bad?
books say 1meg ohm or higher is good but which of this reading is the right one? in my case I took the 20k setting, my sensors read 1.25k and 1.57k and that how I decided they were good sensors and installed them....
was I wrong or right?
for me this sensor I'm testing is bad....
20k and the reading is 0.67
then I changed the setting at 2000k and reads 031
then I changed it to 200k and read 21.8
changed it to 2000 ohms and reads 547
changed it to 200 ohms and reads nothing no reading....
which of these reading is the one you take? is that a good sensor? bad?
books say 1meg ohm or higher is good but which of this reading is the right one? in my case I took the 20k setting, my sensors read 1.25k and 1.57k and that how I decided they were good sensors and installed them....
was I wrong or right?
for me this sensor I'm testing is bad....
Last edited by sparks11; 04-22-09 at 07:17 PM.
#55
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I have to get this out , that is the most rediculously small picture I have ever seen someone upload in all the years I've been using the world wide web. hahahahahaahah thank god i lowered my monitor res, ahh, yes, it's a multimeter and not a candy corn ... rofl
ok now i'll read what you've been saying
ok now i'll read what you've been saying
#56
Lexus Champion
Direct Current volts section 20, 200, 200M, 2000M
V~ Alternative Current and I have 200, 750
A Amperes 200 microamps,2000 microamps,20milliamps,200milliamps [0.2 AMPS]
I want to test the ecm again.. and the wires too, what settings should I use to do that? you should test the wire using the resistance mode, set to the lowest ohms [probably on yours, 2 ohms or 20 ohms, the lowest of them] , you test the wires with it not connected to the ECU
V~ Alternative Current and I have 200, 750
A Amperes 200 microamps,2000 microamps,20milliamps,200milliamps [0.2 AMPS]
I want to test the ecm again.. and the wires too, what settings should I use to do that? you should test the wire using the resistance mode, set to the lowest ohms [probably on yours, 2 ohms or 20 ohms, the lowest of them] , you test the wires with it not connected to the ECU
#57
20k and the reading is 0.67 (670 ohms)
then I changed the setting at 2000k and reads 031 ('m confused, was this .031?)
then I changed it to 200k and read 21.8 (21.8 K ohms)
changed it to 2000 and reads 547 (547 ohms)
changed it to 200 and reads nothing no reading....
I assume that all of these readings are from the same sensor. If that is true, my guess is that your DVM has problems. You can verify if you DVM is working properly by going down to the local radio shack, and purchasing some resistors in several different ranges, such as 100 ohms, 1 k ohms, 100 k etc.
Resistors are cheap you can buy several different values for less than $5.00.
Resistors come in different watt rattings, for this test, you really don't care what the wattage is (1/8 watt are gennerally cheaper,).
Check the meter with these resistors (resistors are rated at 5 to 10 % tollerance). This means that a 200 ohm 10% resistor could read 190 ~ 220 ohms. Measure the resistors to check the meter, and get yourself familar with reading resistance. It is very important to know what ranges you are actually in, even more so than the displayed digits.
From your readings, I would say either the sensor is bad, your meter is bad, or a slim possibility you are reading it wrong. With the resistors from radio shack (or FRYS) you can figure out which.
then I changed the setting at 2000k and reads 031 ('m confused, was this .031?)
then I changed it to 200k and read 21.8 (21.8 K ohms)
changed it to 2000 and reads 547 (547 ohms)
changed it to 200 and reads nothing no reading....
I assume that all of these readings are from the same sensor. If that is true, my guess is that your DVM has problems. You can verify if you DVM is working properly by going down to the local radio shack, and purchasing some resistors in several different ranges, such as 100 ohms, 1 k ohms, 100 k etc.
Resistors are cheap you can buy several different values for less than $5.00.
Resistors come in different watt rattings, for this test, you really don't care what the wattage is (1/8 watt are gennerally cheaper,).
Check the meter with these resistors (resistors are rated at 5 to 10 % tollerance). This means that a 200 ohm 10% resistor could read 190 ~ 220 ohms. Measure the resistors to check the meter, and get yourself familar with reading resistance. It is very important to know what ranges you are actually in, even more so than the displayed digits.
From your readings, I would say either the sensor is bad, your meter is bad, or a slim possibility you are reading it wrong. With the resistors from radio shack (or FRYS) you can figure out which.
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have to get this out , that is the most rediculously small picture I have ever seen someone upload in all the years I've been using the world wide web. hahahahahaahah thank god i lowered my monitor res, ahh, yes, it's a multimeter and not a candy corn ... rofl
From your readings, I would say either the sensor is bad, your meter is bad, or a slim possibility you are reading it wrong. With the resistors from radio shack (or FRYS) you can figure out which.
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thanks for the info.. I will test the wires and ecm as soon as I get another voltmeter and we can compare the same readings with the same sensor I tested today...but from what I see everything point out I installed bad sensors!!!
#59
Ps, you could bring the meter down to radio shack, cause if it fails the resistor check you will need another one, a basic one is ok. If you purchase a new meter, make sure that it has a INPUT IMPED of 10 meg. With 10meg input imped you can ohm out ecm pins without having to worry about damaging the ecm