Does anyone know the correct ohm readin when testing a knock sensor?

 

It should be around 550 kohms.

 

hmm so a reading of .55 ohms would be correct?

 

Only if your multimeter was set in the megohm range. In which case the resistance is actually .55 megohms (=550 kohms). .55 ohms would definitely be bad, that would indicate an internal short.

 

I also just checked my car OBDII with the palm and got a 0525 code which the palm indicated problems with the knock sensor. I've heard people say that one way to check it is to take it out and drive to see if there is a difference. I was wondering if there was a different way of testing it i.e, meter. My question is, with the knock sensor, when it goes bad is it an all or nothing deal (where the knock sensor is either completely dead or is completely ok) or is it more of problem where the KS can just completely start to go bad ?

 

Good question, I would like to know that too?
All or none?

 

i actually saw some people post here that even though they had a correct ohm reading on their KS the KS was still bad after further investigation. . .
just something to keep in mind...

Sam

 

Well from what I noticed it was an intermitent problem with me
ocassionally I would have this hesitation issue throughout the rpm range...then after about month three of the off and on situation it was a steady issue. I replaced my injectors per dave b's advice which didnt fix it...had it scanned today and sure enough knock sensor. Shoulda listened to my gut feeling on that one, but hey newer injectors too..haha

 

Anyone else know what the ohm reading would be? I need to know so I can test and possibly buy one off of ebay soon. I have to go to the races and make my car stop hesitating. I don't know if this will cure it, but I will try it. My dad had an ohmeter and I can test it out tomorrow.

Someone that knows please post for second opinions.

 

The KS reading should be 550 K-Ohm. Make sure your meter is capable of reading this high of resistance. Some have reported bad KS that still read 550 kOhm.

Read the 4th Gen How-To Sticky. I have a lengthy post on knock sensor diagnosis, replacement, etc...

 

550 kohms, like the guy said earlier.

Knock sensors can fail intermittently (happened to me). If your KS gives you the correct resistance but you still suspect it, disconnect the harness from the sensor and run a 550 kohm resister in its place. If your car feels like it has more power in the low-midrange, then your KS was bad. The resistor has to be connected to the KS signal wire in the harness, the other end to ground.

 

okay, thanks guys. That is helpful. I didn't know it could fail intermittently. I just thought once it failed once, it was bad. I guess that is why my car hesitates sometimes and then not others. Is there any reason why it is not spitting a code? Do I need to just go out and drive it and let it snort and buck and then come home right away and check for codes?

Thanks, gansemer, I will read that.

I wasn't trying to say anyone was wrong, just trying to get different opinions. I got that, and they are all the same which is good.

 

If the KS is bad once, it should spit the code. But remember, the KS code is a "ghost" code, meaning it won't light the check engine light. It will exist, but you won't know about it unless you scan your codes somehow.

Also, beware of the wiring harness leading to the KS. I'm planning on replacing my harness along with my KS this weekend. The harness is suspect because I can use an ohm meter and get a reading of about 600-700 ohms. But as I giggle the wiring harness, the reading will occasionally show a loss of continuity.

Last tip, be sure to clean the connectors in the wiring harness of corrosion. The connectors are usually pretty weather-proof, but I found a little light layer of stuff on mine. It appears that stuff did affect the resistance passing through it a little, but it shouldn't have been enough to trigger the KS code on its own.

Good Luck

Mike