How do i know if my comp detects Knock???

Discussions concerning the M7790 cpu

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silva2786
 

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Joined: Wed Mar 24, 2010 12:30 pm

How do i know if my comp detects Knock???

Post by silva2786 »

How do i know if my comp detects Knock???
I KNOW IS A NOOB QUESTION BUT i ran 18 Degrees under 14psi' spiking 20 degress and still no knock sensor code or anything wierd.... can my knock sensor be bad even doe im not getting a code for it. Or is it that im really not getting knock for some wierd reason?
Matt
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Re: How do i know if my comp detects Knock???

Post by Matt »

Your car will start pulling out timing when it starts detecting knock. It also has an internal counter. If it counts too much knock it will switch to knock tables. Logging during your runs will confirm this when you compare timing values in the log against those on your timing map. If it starts going south and deviating from averages in the timing map then something else is happening

Making your knock fuel/timing tables really low is a good way to know when it has switched to them (monitoring these tables will be something available in the future to highlight when they are used)

Kock DTCs are only raised if there is a connectivity issue with the sensor. If it is connected properly, and valid resistance there will be no DTC. But if its detecting knock all the time this wont flag a problem

Turning off knock feedback in the 'feedback flags' is another way to check. Use knock sensing headphones to check otherwise if suspicious knock is really occuring
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