Tired of code 52...

[bobpogoman]

i made a ks re-wire...just re-veryfied the whole thing...its grounded on both side (the insulation) theres no coniunuity between the signal and ground...any one know what else can happen to make a re-wire go bad???....and how do we check the ks themselves (havent found ne post theres a LOT of pages talking about ks so its really long to find)
thanks..john

 

[steve_mk3]

Hi John-
The other night I searched for information on KS. What i found is that in order to properly test the sensors themselfs you would need a oscilloscope.
The KS put out a wave signal that you cant test with a conventional VOM.

So i performed test that are similar to what you may have goon thru-
1- end to end test of the rewire itself making sure I had contiuity between the KS end and the ECU plug
2- Tested each rewire to make sure there was no continuity between the sheilding and the core of the wire.
3- I tried tapping on the knock sensors with a vom connected to the wire and I could not get any voltage- As expected but I thought I would try.
4- I tested the shield ground to the battery ground, I found that I did not have a ground.
5- Found a good ground connector under the dash to the far right side, It was a 12 mm nut.
6- connected just one side of the rewire to the ground

* success!! no more code 52.

So what I learned from this is the signal is extreamly sensitive. Properly grounding one end of rewire should work better than grounding both ends. Grounding both ends may actually induce noise.

I would thaink that you can connect both inputs to the ecu to one good knock sensor for testing purposes only. I have not verified this, it was going to be my next step after rechecking the wireing.

Keep in mind that it can only be 3 things that cause a 52
- Bad sensor
- Bad wire
- bad ecu
Most probable cause it the wireing, double check and verify the ground is good.

Hope this helps
Steve

 

[bobpogoman]

kk thanks a lot...gotta check my both ground (they are both made with a simple metal-screw lol....) and for the ks themselves...when i hit them with something i get some voltage...( at 200 MV) but for now i gotta check my ground cuz theres no continuity between shield and signal....and theres a signal between connector and ecu pin....ill reply if good ground fixed my problem

 

[chriso]

connected just one side of the rewire to the ground

So what I learned from this is the signal is extreamly sensitive. Properly grounding one end of rewire should work better than grounding both ends. Grounding both ends may actually induce noise.

Which side did you ground, the engine side or the ECU side and do you think it makes any difference which one you do?

 

[bobpogoman]

:cry:

Which side did you ground, the engine side or the ECU side and do you think it makes any difference which one you do?

re-grounded the ecu side...then re-ground engine side (so both on a 12 and 14 mm nut)... tryed...not fixed :S

 

[bobpogoman]

the ks thing is bitch loll....but just a question...when i set my multimeter to the (beep) sound when theres continuity its dont sound when i touch the signal wire and shield wire...but the numbers go up to 1350 approx... and when i set it to ohm (200 2000 do nothing) but at 200k ohm it write 3.4...but i dont know is that a contuinity?? if it is why id ton make the beep sound???

 

[bobpogoman]

and whm for the ground...i MUST use speaker wire???

 

[bobpogoman]

damn ne 1 can help :S....gotta cry im tired of it lol....tryed to fix it all day

 

[shaeff]

only ground one side, lest you create ground loops. ground loops are bad.

-shaeff

 

[bobpogoman]

hi shaeff...i think ur the guy for ks re-wiring...if your still there i please you to help me lol ...kk i removed the ground on the engine side...only grounded the side close to the ecu with the 12 mm bolt here...i havent soldered the wiring close to the ecu for now (in case that its not fixed...i dont want to run out of wire from the ecu connector) what ive made lol :S?

 

[bobpogoman]

dunno if its a mistake...for the ground...i used a 14awg speaker wire...only one so ive put shielding of BOTH thin-net cable together and grounded them...

 

[shaeff]

if your wiring checked out ok, then chances are one or both of your knock sensors are toasted. get them checked out by someone with an o-scope as steve mentioned above. he gave some good info.

-shaeff

 

[bobpogoman]

if your wiring checked out ok, then chances are one or both of your knock sensors are toasted. get them checked out by someone with an o-scope as steve mentioned above. he gave some good info.

-shaeff

kk...but where can i find some one that have those thing...lol i dunt really know whats an oscilloscope and where i can find one :S

 

[shaeff]

have any movie theaters near you? i used to work at a movie theater, and we regularly used o-scopes to work on our projectors.

-shaeff

 

[isnms]

Hi John-
The other night I searched for information on KS. What i found is that in order to properly test the sensors themselfs you would need a oscilloscope.
The KS put out a wave signal that you cant test with a conventional VOM.

So i performed test that are similar to what you may have goon thru-
1- end to end test of the rewire itself making sure I had contiuity between the KS end and the ECU plug
2- Tested each rewire to make sure there was no continuity between the sheilding and the core of the wire.
3- I tried tapping on the knock sensors with a vom connected to the wire and I could not get any voltage- As expected but I thought I would try.
4- I tested the shield ground to the battery ground, I found that I did not have a ground.
5- Found a good ground connector under the dash to the far right side, It was a 12 mm nut.
6- connected just one side of the rewire to the ground

* success!! no more code 52.

So what I learned from this is the signal is extreamly sensitive. Properly grounding one end of rewire should work better than grounding both ends. Grounding both ends may actually induce noise.

I would thaink that you can connect both inputs to the ecu to one good knock sensor for testing purposes only. I have not verified this, it was going to be my next step after rechecking the wireing.

Keep in mind that it can only be 3 things that cause a 52
- Bad sensor
- Bad wire
- bad ecu
Most probable cause it the wireing, double check and verify the ground is good.

Hope this helps
Steve

Sounds familiar

 

[steve_mk3]

Check to make SURE that only one side is grounded. Check to make sure that the place whare your grounding the ONE side is really a ground. Use your meter to check that your on a ground. I cant say this srongly enough, my wireing was correct, but I did not have the shield ground properly and as soon as I connected my shiel to ground the problem was solved.

You cant truely test the KS without an osiliscope in a running car.

I would make sure the wireing is correct. Test from the pin on the ECU plug to the KS end for continuity. Test from the pin on the ECU plug to the shield to make sure there is NO continuity. Test the shield to battery ground to make sure there is continuity. If the above test check 100% then it is probably a bad KS.

I am not sure if this next part will work, but it is what I would try because I dont have a spare KS.
Connect both ECU KS wires to the front KS, if the problem is gone then you know the back one is bad. If you still have the problem connect both ECU KS wires to the rear KS. If the problem is gone then you know the front one is bad. again this may not be a good test just what I would do. If this doesnt work then you may want to buy 2 replacement KS from a good source on the forums that are know working.
The last thing it could be is the ECU itself, that is very doubtful that the ECU is bad, but it could be.

Here is a link to a guy that used an o-scope on his toyoty 4x4 to test the KS.
http://www.cybertrails.com/~bestinthewest/autotips/995Toy88Knock.html

Good luck-
Steve

 

[ashiharausa]

How many knock sensore does 7 mge?
Ive seen only one near the oil filter.

51 error reading too, what does it need to be fix?

 

[supraguy@aol]

7MGE has only one knock sensor, and it's not by the oil filter.
It's under the intake manifold, right around cylinder #3. And why are you asking about the 7mge in the 7mgte section?
Use the search button at the top right side of the screen- search knock sensor rewire. This is a very well-documented repair operation.

 

[DeMoN2318]

And why are you asking the same question in several different threads...and one that is 7 years old...C'MON MAN

 

[steve_mk3]

really old thread
funny seeing this