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Author Topic: K-Line and Can -Bus  (Read 9418 times)
fknbrkn
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mk4 1.8T AUM


« Reply #15 on: March 31, 2022, 03:34:20 AM »

Again. (And again)
This is different canbus network. Hook it at the cluster (or dashboard idk how it named in uk)

Pvdkds is not present in can messages. Youll see it when dump that message. Its 3 bytes long and marked in FR with *S* , check what it means (for the future use iirc)

There is a few unused bytes in 0x488 (iirc) message  which could be used to send any variables with custom routine on a manual transmission cars. Pm me if you interested in this (not for free)
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prj
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« Reply #16 on: March 31, 2022, 03:35:17 AM »

This doc is fine but not all messages are active. But you can activate them of course. Also some things are not present in CAN messages as they are for future use.
For controlling WMI all you need is RPM and Load. Because the maps in the ECU are also based off of Load.

As said above, it's nothing to do with gateway filtering, they are two completely different CAN Bus networks in the car running at different speed even.
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IWay
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« Reply #17 on: March 31, 2022, 04:05:03 AM »


Pvdkds is not present in can messages. Youll see it when dump that message. Its 3 bytes long and marked in FR with *S* , check what it means (for the future use iirc)


OK, different buses.

I checked before posting, *S* page 1634 *S* wird gesendet = will be sent - *(S)* zuk¨unftig geplant = planned in the future.

Both values are *S*, suppose the only way to be sure is to tap the power train Bus and look for it, this will have to wait for the weekend.

looking for the load value I've searched the CAN 51.570 section of the doc for rl and Luftfüllung but couldn't find anything, could it be listed as something else?

Also going back to the K-Line, VisualMeLogger refreshes about 20 times a second whilst logging 10's of readings. Everyone's saying it slow but that speed would be fast enough for what I need, Am I missing something?

Thanks again.
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prj
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« Reply #18 on: March 31, 2022, 04:06:44 AM »

Yes you are missing something.
Any powertrain control should not be done off of diagnostics.
Not only are you eliminating the ability to log the car when your thing is active, but also on K-Line you can not diagnose any module in the car...

All kind of power train control must go through the PTCAN. K-Line is not even an option.
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IWay
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« Reply #19 on: March 31, 2022, 04:13:20 AM »

Yes you are missing something.
Any powertrain control should not be done off of diagnostics.
Not only are you eliminating the ability to log the car when your thing is active, but also on K-Line you can not diagnose any module in the car...

All kind of power train control must go through the PTCAN. K-Line is not even an option.

Cool, Cheers.
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IWay
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« Reply #20 on: April 03, 2022, 03:34:52 AM »

Hello,

I tapped the power train bus yesterday and as expected the Boost & IAT aren’t there:( (FRE07E0 RTP.PDF can’t be completely relied upon for the PQ34 platform).

Standard ID: 0x588       DLC: 3  Data: 0x08 0x00 0x80

So unless someone knows of a quick easy way to enable the Motor 7 messages on the bus, my next plan is,

As part of my project I’ll have a W-M low level warning which will require wiring back to the Arduino, so running a few more wires won’t make much difference.
I already have a separate boost gauge (uses voltage as a signal) which I can tap, this will give me my boost pressure reading.

All good so far.

As for the IAT I’m pretty sure I can’t tap this sensor as it uses resistance, this leaves me with either adding a dedicated IAT sensor or calculating the IAT from the values I can obtain.
I would like to calculate the IAT but not sure what the formula would be, I think it might use MAF, RPM, Ambient air temp, boost, engine capacity, load but what it would look like is beyond me at this point, any assistance with the formula would be most appreciated.

I have also considered adding a dedicated IAT sensor and then sending the readings for the Boost, IAT & W-M level back to another Arduino in the engine bay and adding these readings as custom Can messages to the Power Train bus, this would be a neat solution but I would be just making work for myself and adding complexity.

Thanks
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BlackT
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« Reply #21 on: April 03, 2022, 07:23:55 AM »

Wtf? Just use load
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IWay
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« Reply #22 on: April 04, 2022, 01:27:39 AM »

Wtf? Just use load


I see where you're coming from but,

How do I calculate the load from the available values?

               ml_w
rml = --------------- * 100%
              MLMAX

I can't see either rml, rl, ml_w or MLMAX listed in the FR as can messages?
                
Also I want some more granularity and to display the speed, RPM, boost & IAT together with recording the maximum values.

Also the FR "Audi_R4-5V_T_132kW_ME7.pdf" says the RPM is Byte 4 & 3 in message ID 280, but it's not it's 5 & 4.

I have also noticed that after blipping the throttle the RPM drops down to double or even single digits, is that supposed to happen?

Thanks
« Last Edit: April 04, 2022, 06:27:01 AM by IWay » Logged
BlackT
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« Reply #23 on: April 04, 2022, 06:08:24 AM »

0x280 byte 2,  you can use this value for load.
 You don't need to calculate anything if you IRL and IOP are right

If FR say rpm is at 3 and 4 than there it is
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IWay
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« Reply #24 on: April 04, 2022, 07:14:45 AM »

Your a gent Smiley

So is 0x280 byte 2 rl?

Getting some where now, see attached - the RPM is definitely 5 & 4, 4 & 3 doesn't make any sense.

Not sure what is happening at the start of the file, probably something to do with where the key is in the ignition.

PS
The car wasn't moving when this was taken.
« Last Edit: April 04, 2022, 07:47:36 AM by IWay » Logged
prj
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« Reply #25 on: April 04, 2022, 02:33:23 PM »

Your a gent Smiley

So is 0x280 byte 2 rl?

Getting some where now, see attached - the RPM is definitely 5 & 4, 4 & 3 doesn't make any sense.

Not sure what is happening at the start of the file, probably something to do with where the key is in the ignition.

PS
The car wasn't moving when this was taken.

It is 3 and 4. LoHi byteorder.
If you only spent 1% of the time thinking instead of writing walls of text...
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IWay
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« Reply #26 on: April 05, 2022, 03:06:52 AM »

It is 3 and 4. LoHi byteorder.
If you only spent 1% of the time thinking instead of writing walls of text...


I'm confused,

Counting the bytes 0 -7 then it's 4 -3, but the FR uses 1 - 8, using 0 -7 would place the other values at the wrong Byte.

Have a look at the spread sheet I posted 4 - 3 doesn't add up, using bytes 5 - 4 and byte count 1 - 8 is the way it appears to work?






 
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BlackT
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« Reply #27 on: April 05, 2022, 03:17:45 AM »

Lets make this:
If you see 64(byte3) and 13(byte4)
How much RPM is that?

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IWay
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« Reply #28 on: April 05, 2022, 04:00:22 AM »

 Embarrassed Embarrassed Embarrassed Embarrassed Embarrassed Embarrassed Embarrassed Embarrassed

Sorry must be going mad, it is 4 - 3, must have messed up the formula in excel at some point.

I'll go away & beat myself with a big stick.

Or talk to the wife which can be just as painful. Wink Wink

Thanks for your patience.
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prj
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« Reply #29 on: April 05, 2022, 04:23:47 AM »

I'll go away & beat myself with a big stick.
That would be oddly satisfying to watch.
But at least you realized the problem.
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