Intermittent SES w/knock sensor code
Thread Starter
Racer
Joined: Mar 2003
Posts: 309
Likes: 0
From: Las Vegas NV
Intermittent SES w/knock sensor code
I have a '93 that is displaying an SES light after I start the car. The SES typically goes out after a few minutes. The car is throwing a knock sensor code. A few weeks ago, I got under the car and cleaned the connections on the knock sensors. That cleared up the SES for about a week and a half, then the issue returned. My question is, based on past experience, am I better off changing out the sensors first, or the connectors? I read a previous post where an individual tested the knock sensors and they checked out good, but could not get the SES to go away until the sensors were changed.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
I have a '93 that is displaying an SES light after I start the car. The SES typically goes out after a few minutes. The car is throwing a knock sensor code. A few weeks ago, I got under the car and cleaned the connections on the knock sensors. That cleared up the SES for about a week and a half, then the issue returned. My question is, based on past experience, am I better off changing out the sensors first, or the connectors? I read a previous post where an individual tested the knock sensors and they checked out good, but could not get the SES to go away until the sensors were changed.
One thing I do recall from my testing is that the two original knock sensors had quite different resistance, even though both were within specs. The replacements were much more closely matched. I have no idea if that is significant.
When I replaced connectors I did not even get the temporary improvement you mention after cleansing yours, so I would at least take a second look at them, good luck.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
I would check the connectors first, especally since cleaning them cleared up your problem once, these have a reputation of failing when they get old..If you do find it to be the sensors, check the FSM for the torque specs, if there not torqued close to spec sometimes they won't give accurate readings. I have known more then one person that had problems after putting them in without torqueing to spec..Also they should come with sealer already on them, using the wrong sealer can cause them not to work properly...WW
Last edited by WW7; Jul 19, 2011 at 09:26 AM.
Le Mans Master
Joined: Mar 2001
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
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St. Jude Donor '12
My 92 did the same thing. All tests indicated knock sensors were good.
Had to do some other work and decided to just replace them. Codes went away with new sensors
Had to do some other work and decided to just replace them. Codes went away with new sensors
