Knock sensing

[AVP]

I noticed that on 1.1.88 there are a few add ons on the knock sensors. Anyone already figured out how they need to be setup on an audi 5cyl engine? Do they perform now?

[GintsK]

Seems new knock sense do not work on 1.1.88. It works on non released 1.1.89.
I hope on 1.1.90

Knock_alternative itself looks very promising. In Russia guys use it for long while.

Blury part is knock sensor sequence:

Knock channel.
0 means sensor 1 for all cylinders
255 means sensor  2 for all cylinders.

If you need to combine the sensors-events it is more tricky:
0 comes from 00000000 binary
255 comes from 11111111 binary

So if you want to use sensors accordantly to cylinders (spark events) , then for example
10101010 (170) will switch sensor for every spark event.

1 at the  beginning belong to bottom cylinder in ignition output table (non used one if it is not 8cyl engine).
0 at  the end belong to top cylinder in same table (used always).

any desired combination except 11110000 (240) and 11110001 (241) can be used. These two disables knock.

Converting binary<-> decimal can be done by windows native calculator.

You can read it in different "language" in 1.1.26 description here:
http://www.vems.hu/wiki/index.php?page=GenBoard%2FUnderDevelopment%2FFirmwareChanges

Of course you have to be sure about hardware present inside ECU for second sensor.

Gints

Regarding knock alternative please read this wiki page. If you have questions, just ask.
http://www.vems.hu/wiki/index.php?page=MembersPage%2FAndrey%2FKnock

Gints

[BigD]

So just to confirm, if I have the top 6 inputs going to cyl 5-3-6-2-4-1 (bottom up), and if I have ec18 pin 1 on cyl 1-3, and cyl 4-6 on pin 2, then 170 should work for me?

Also, I have 3.6 and they deleted knock 2 in favor of an analog input. I added a jumper from the other knock chip pin to pin 2. So when it says pin 1 = knock 1, that's the one that's used when a bit is 0? (in other words, in my case, bit 0 = cyl 1-3, bit 1 = cyl 4-6)

[GintsK]

Yes, 170 seems correct in this case.
But double check knock input. Just jumper could be not enough: sometimes two 22kOhm resistors and one cap for input also missing.

[BigD]

Thanks! What's the best way to verify it? Turn on logging and smack the engine? Would it log with the engine off?

[BigD]

Can you tell me where to look for these components? I read the knock page but I'm not clear about where these resistors need to be...

http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FKnockSensor

I guess one needs to be next to r2? But where should the others be? I'm not sure what the diagonal position is.

[GintsK]

I doesn't log with engine off. And it doesn't log also with engine running on 1.1.88  Until you reach something like 8000rpms 

You see diagonal pads for two SMD parts? Here should be soldered one resistor an one capacitor.

[AVP]

already by looking at the vems link, it looks quite complicated to me!

the thing though is that still on 1.1.88 the knock sensing does not work..

Gintis, for 2 knock sensors which number 1 sees cylinders 1,2 and 3 and knock sensor number 2 looking at cylinders 4 and 5, does that mean that the channell should be 21 as you have on your settings?

also to properly configure the knock sensors, does it mean that we should know the firing order of the cylinders so that the sensors can detect at the right time?

[GintsK]

What is complicated?

21 decimal is same as 00010101 binary - seems incorrect.
h[2]  sensor
3        0     
5        1
4        1
2        0
1        0
x        0
x        0
x        0

so 00000110 is 6 decimal (3 entries on bottom has no sense for 5cyl engine - it can be 0 or 1 as well)

[mattias]

For me personally, even if I can figure out how the system works - this stuff should be in a more "visual" dialog. I'll put that on the wishlist.

[BigD]

I doesn't log with engine off. And it doesn't log also with engine running on 1.1.88  Until you reach something like 8000rpms 

You see diagonal pads for two SMD parts? Here should be soldered one resistor an one capacitor.

Ok so I took the box apart, I do have the resistor next to R2, but the back side of the board looks just like above, just 4 solder blobs, no parts. So my knock 2 doesn't work?

I was digging through my logs, I've got logged values for all 6 cylinders, and even have some knock adjust during deceleration:

[GintsK]

Then second sensor is simply disconnected from knock chip.

Before you looking at knock retard action, you have to adjust knock noise levels for each cylinder (you can try it juast for three front cylinders). I think best is about 1/4..1/3 of maximal 1012. It would be something like 30....80 at low rpms and 250....350 at full load. without knock of course.

[z0tya]

Then second sensor is simply disconnected from knock chip.

Before you looking at knock retard action, you have to adjust knock noise levels for each cylinder (you can try it juast for three front cylinders). I think best is about 1/4..1/3 of maximal 1012. It would be something like 30....80 at low rpms and 250....350 at full load. without knock of course.

but need unofficial 1.1.89 for it?

[GintsK]

I hadn't any knock noise with 1.1.88. May be BigD have!

[BigD]

Then second sensor is simply disconnected from knock chip.

Before you looking at knock retard action, you have to adjust knock noise levels for each cylinder (you can try it juast for three front cylinders). I think best is about 1/4..1/3 of maximal 1012. It would be something like 30....80 at low rpms and 250....350 at full load. without knock of course.

How is it possible then that I have reasonable and consistent values logged for all 6 cylinders with an alternating knock sensing strategy (85)? I should be seeing nothing for every other cylinder...