Datalog Measuring Oil Level through MHD

[Anon1]

Looks like the N54 folks have found a way to get the engine OIL level displayed in MHD and we should do the same for N55.

See here for more details, https://www.spoolstreet.com/threads/measuring-oil-level-through-mhd.9329/

I think the approach for this is:
- Find the routine for oil measurement
- Find the name of the of the oil level value
- Find that address in the 98G0B/9E60B/etc by using the closest damos
- Define the custom UserChannels.xml

I think I may have found the routine/value
Oil_niveau
" lniveau Level vom NS"
UBYTE
h_q1_mm
1
100
0.00
255.0

FORMAT "%5.1"

 

[houtan]

Thanks for starting the thread. This is the xml language for the n54:

<ActualValue ReqBlock="D9,5E" Size="1" DataA="0.29296875" DataB="0.0" Prefix="C0" Units="mm" RoundingDigits="2">
<Text xml:lang="en">$ Oil Level</Text>

So we need to find the ReqBlock info?

 

[houtan]

File name should be: 98G0B_UserChannels.xml

This goes in the MHD folder where you save customs maps or where your data logging folder is.

This is the format that I have for the xml file:

<?xml version="1.0" standalone="yes"?>
<ActualValues>
<ActualValue ReqBlock="D9,5E" Size="1" DataA="0.29296875" DataB="0.0" Prefix="C0" Units="mm" RoundingDigits="2">
<Text xml:lang="en">$ Oil Level</Text>
</ActualValue>
</ActualValues>

 

[wheela]

File name should be: 98G0B_UserChannels.xml

This goes in the MHD folder where you save customs maps or where your data logging folder is.

This is the format that I have for the xml file:

<?xml version="1.0" standalone="yes"?>
<ActualValues>
<ActualValue ReqBlock="D9,5E" Size="1" DataA="0.29296875" DataB="0.0" Prefix="C0" Units="mm" RoundingDigits="2">
<Text xml:lang="en">$ Oil Level</Text>
</ActualValue>
</ActualValues>

Wow, does this mean you found it already? I'm 9e60b, so guessing addresses will be different for me?

 

[houtan]

Not yet. Sorry, just showing how the format looks like.

 

[EasyTelemetey]

Subscribed

 

[fstbtstr]

Don't have an "Oil_niveau" RAM address, but how would you convert a RAM address you want to log to "ReqBlock" which doesn't look like an address?

 

[fstbtstr]

Anyhow, this is my current guess where Oil_niveau lives in 98G0B RAM: 0xC0002089. Now if somebody could tell how to get that into ReqBlock, than it can be tested either by me or somebody else.

 

[houtan]

Anyhow, this is my current guess where Oil_niveau lives in 98G0B RAM: 0xC0002089. Now if somebody could tell how to get that into ReqBlock, than it can be tested either by me or somebody else.

Thanks! Maybe @carabuser can help us out?

 

[carabuser]

<?xml version="1.0" standalone="yes"?>
<ActualValues>
<ActualValue ReqBlock="20,89" Size="1" DataA="0.29296875" DataB="0.0" Prefix="C0" Units="mm" RoundingDigits="2">
<Text xml:lang="en">$ Oil Level</Text>
</ActualValue>
</ActualValues>

Just as simple as putting the last 4 digits of the RAM address in the req block.

 

[houtan]

<?xml version="1.0" standalone="yes"?>
<ActualValues>
<ActualValue ReqBlock="20,89" Size="1" DataA="0.29296875" DataB="0.0" Prefix="C0" Units="mm" RoundingDigits="2">
<Text xml:lang="en">$ Oil Level</Text>
</ActualValue>
</ActualValues>

Just as simple as putting the last 4 digits of the RAM address in the req block.

Thank you and @fstbtstr. I will try this out later today.

 

[fstbtstr]

Thank you and @fstbtstr. I will try this out later today.

no problem, let's see how it works.
As for the custom logging channel definitions, what does Prefix do? There're multiple RAM sections in both N54 and N55 DMEs such as 0xCXXXXXXX and 0xDXXXXXXX, and the last 4 address digits are not enough to define the actual address unambiguously. Do I understand it correctly that Prefix "C0" actually indicates if the address is in, say, 0xC0XXXXXX region?

 

[houtan]

@carabuser, @fstbtstr,

There is some progress. The parameter oil level shows up now and doesn’t freeze up the ability to log.

However, the oil height output seems to be wrong. It stays at 5.27 mm. It should read in the 70s on my car right now.

Any ideas on what would cause this?

Screenshot attached.

 

[fstbtstr]

First off, do you have 98G0B ROM? Second, I am not entirely sure that oil level height conversion is the same between the N54 and N55. Although conversion probably should be the same since it's a byte-sized value as well with the same(?) range.
Does the oil level reading change at all? Is this the reading before or after CIC/cluster oil level became available?
I should be able to log my 98G0B next week and maybe try to look into 96*** DME, but don't really have time to do it this weekend
P.S. eyeballing 9E60*, seems like the address is 0xD00024E0, but this is very tentative. I wonder if Prefix will have to change to D0 instead of C0.

 

[houtan]

Yeah I am 98g0b.

You know what, I do not wait for oil level measurement to show up on the CIC. I will try again and wait for the CIC to get a read out

 

[fstbtstr]

Yeah I am 98g0b.

You know what, I do not wait for oil level measurement to show up on the CIC. I will try again and wait for the CIC to get a read out

We'll need to understand what ram address MHD is actually requesting, as I said, there're a few. It is possible it's reading something from DXXX XXXX range. Or I'm just wrong. I do see that it doesn't get set until some conditions are met, don't quite understand what they are.
Anyhow, my guess for 9e6 is 0xc000230e now

 

[carabuser]

no problem, let's see how it works.
As for the custom logging channel definitions, what does Prefix do? There're multiple RAM sections in both N54 and N55 DMEs such as 0xCXXXXXXX and 0xDXXXXXXX, and the last 4 address digits are not enough to define the actual address unambiguously. Do I understand it correctly that Prefix "C0" actually indicates if the address is in, say, 0xC0XXXXXX region?

You are correct but the RAM only goes up to ffff.

 

[houtan]

Just verified. After the cic got its oil level readout, MHD still said 5.27

 

[fstbtstr]

Just verified. After the cic got its oil level readout, MHD still said 5.27

thanks! I'll log it next week, let's see if i get the same value or perhaps there's a scaling issue, too.
P.S. on another thought, it's not clear what "height" Oil_niveau is actually tracking. It could be the height from the top of the sensor down to the oil level. In that case, your Oil_niveau (without applying conversion) would be 18mm indicating full oil level. Is that the case - your oil level is at 100%? We might actually be interested in another var like ozniv ("Ölniveau ungefiltert in [mm]") at d00031a3, and that would not need any conversion. (Prefix D0, ReqBlock 31,A3)?

 

[houtan]

Sounds good.

I know when I measure my oil level with my foxtool OBD scanner, my oil level readout is 73.xx mm, which is about one quart over fill. So I was expecting to see a similar value in MHD.