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Knock Sensor Information

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The knock system on the Falcon is a separate chip within the PCM case. They use a ATM-40 compatible HIP-9010 knock chip from what I can tell (not 100% confirmed yet). The datasheet for this chip is attached.

Every cycle the PCM sends the following values to the knock chip which are packed into 5 bytes. These values can be datalogged with our datalogging software which will be available soon.

cd_sca=  The value of the pre-scalar being sent to the ATM-40
cd_conf_y =  Test/selection channel chosen on ATM-40 IC
cd_fil_nx = The next bit point value of the bandpass filter centre frequency to be sent to the ATM-40
cd_gn_nx = The bit point value of the basic gain to be used to determine the next gain setting to be sent to the ATM-40
cd_int_nx = The next bit point value of the integrator time constant to be sent to the ATM-40 


These values are generated from the various tables in the editor found under "knock sensor". Eg the window frequency etc is changed based on rpm and so is the integrator time constant. Most of this would never be changed.

The PCM then reads back the knock energy detected each cycle and compares it to its sensitivity window for each cylinder. This is then used to determine spark retard.




The following values can be datalogged regarding the knock sensor. These descriptions will be improved and catagorised as time goes on.






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  • 1 year later...

There are individual knock trims per cylinder and also an average knock adder that you can log. The following two items are what your want to log

Individual cylinders


Average total


Regarding spark have a read of the link below. Short answer is you can pick either. 


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  • 3 months later...
1 hour ago, Romulus said:

Bump. How can sensitivity be reduced?

Open PCMTec and type in "knock sensitivity" into the search bar and it'll come up. The enthusiast version has the sensitivity tables and the professional version has the knock window variables as well.

In my experience you don't want to reduce the numbers in the tables by more than 20% otherwise the knock sensors won't work.

You can work out what the safe numbers are yourself if you are inclined, by using knock ears, logging and spending the time to dial the tables in entirely. In this regard it's similar to dialing in cam timing. You need to have free dyno time and know how to do it yourself, or have money to burn.

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  • 6 months later...

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