Knock Sensor Question
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11 Second Club
Joined: Aug 2012
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From: Middletown, DE
Knock Sensor Question So recently I fixed my car from an instrument cluster issue due to a ECU full of water and some corroded pins 
The other night I got a check engine light and when I diagnosed it, my OBDII told me I basically had a knock sensor that was getting low voltage.
Im wondering if it is the knock sensor or the pin in the ECU (considering there was water in there for about 2-3 months).
Is there a way I can tell I REALLY have a bad knock sensor and it is not just the ECU with a bad pin?
The car has been driving great however, but i feel a little power loss in the lower RPMs.
Thanks in advance!
The other night I got a check engine light and when I diagnosed it, my OBDII told me I basically had a knock sensor that was getting low voltage.
Im wondering if it is the knock sensor or the pin in the ECU (considering there was water in there for about 2-3 months).
Is there a way I can tell I REALLY have a bad knock sensor and it is not just the ECU with a bad pin?
The car has been driving great however, but i feel a little power loss in the lower RPMs.
Thanks in advance!
Water damage does curious things to contacts.
You can identify the contacts at the ECM plugs & try to (re)clean the pins & connectors... & you could identify the two, individual voltage wires for the two knock sensors and compare them with a digital voltmeter.
And/or, you can swap the two plugs to each sensor and see if the trouble swaps.
While this entails some work to remove the intake, you could alternately identify the wires leaving the ECM, and cut & swap, then re-splice.
You can identify the contacts at the ECM plugs & try to (re)clean the pins & connectors... & you could identify the two, individual voltage wires for the two knock sensors and compare them with a digital voltmeter.
And/or, you can swap the two plugs to each sensor and see if the trouble swaps.
While this entails some work to remove the intake, you could alternately identify the wires leaving the ECM, and cut & swap, then re-splice.
Last edited by gMAG; Mar 15, 2013 at 11:22 AM.
Thread Starter
11 Second Club
Joined: Aug 2012
Posts: 730
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From: Middletown, DE
Yeah I looked at that. I might just replace the knock sensors and the harnesses anyway though since they seem to go bad fast.
Is it okay to still drive the car? I have a 93 octane tune so i figure as long as i am running 93, it should be alright?
Is it okay to still drive the car? I have a 93 octane tune so i figure as long as i am running 93, it should be alright?
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Joined: Mar 2013
Posts: 5
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From: mesa arizona
I work on Chevy trucks all the time and have noticed that if water gets under the intake and down on the knock sensor they tend to go bad.when I replace them I usually out silicone to seal the rubber plug that covers them and the problem goes away
