[lsutiger607]

Originally Posted by DWR

These are generic OBDII PIDS. They are commonly listed on the internet http://en.wikipedia.org/wiki/OBD-II_PIDs . But there is a trick. Many PIDs have more than one parameter and the data is in multiple bytes. In the csv, you will see Mode&PID. The mode is always 1. The next 2 charaters are the PID, but then in the formulas you will note A,B,C,D etc. Those are the bytes.

For those who are looking for non standard PIDs I am going to suggest you work with TestO. I published the list of know parameters with translation from German in a previous post. http://www.e90post.com/forums/showpo...&postcount=175

DWR, thanks so much for all the good info in this post. I am trying to read my E92, engine data with an Arduino and a CAN BUS shield. I have successfully read parameters such as RPM, engine run time, Coolant Temp and ambient pressure using the standard PIDs but have been unable to read things like oil temp, fuel flow and fuel pressure. It seems I have run up to the roadblock of custom PIDs described in this post and in others. I thought I had that problem solved after downloading the excel sheets you posted above with the German Translations but have been unable to decipher them.

So my question is how do I determine the PIDs from this spreadsheet for use in reading the Car's CAN BUS? For example, I am successfully reading Mode 1 (RPM) PID 0C from the car but the spreadsheet describes in column 'B' an ID of 0x182F (which when used in my code, returns no value). Column A describes a PID0C, which again, is correct. What is the column B describing? The column A PIDs are only displayed for a fraction of the total document.

Thanks in advance.

[DWR]

Originally Posted by lsutiger607

DWR, thanks so much for all the good info in this post. I am trying to read my E92, engine data with an Arduino and a CAN BUS shield. I have successfully read parameters such as RPM, engine run time, Coolant Temp and ambient pressure using the standard PIDs but have been unable to read things like oil temp, fuel flow and fuel pressure. It seems I have run up to the roadblock of custom PIDs described in this post and in others. I thought I had that problem solved after downloading the excel sheets you posted above with the German Translations but have been unable to decipher them.

So my question is how do I determine the PIDs from this spreadsheet for use in reading the Car's CAN BUS? For example, I am successfully reading Mode 1 (RPM) PID 0C from the car but the spreadsheet describes in column 'B' an ID of 0x182F (which when used in my code, returns no value). Column A describes a PID0C, which again, is correct. What is the column B describing? The column A PIDs are only displayed for a fraction of the total document.

Thanks in advance.

I appreciate the kind words but to be frank, I'm really not interested in Arduino CAN BUS projects. You are welcome to use the information I have provided in any way you choose, but it was not provided expressly for the application you are working on. Perhaps you should start a thread on your topic?
Best of luck.

[robnitro]

Originally Posted by f00dstamps

Thanks, robnitro. I got it working when I reloaded the file and PIDs. Unfortunately I appear to be getting significant boost leak. I get readings of up to 900 when only boosting up to 15psi. I did not log a higher run this time but I've seen numbers of up to 1200 on 32psi runs.

Does anyone know if BPC 2+ disables the NOX sensor readings? I am getting no readings (-100 PPM) on the NOX PIDs.

is it 900 at 15 psi for the "perbar" or the other maf reading which is just mg/r (mg per stroke as vag com used to give us maf)???

If its per bar reading, example 900 at 15 psi, and you got 1800 for the other number, that means you are looking at the right reading. (1800/2 bar absolute=900 approx)
In that case yes, you probably have a boost leak because for 1 bar air, its around 500 mg/str

[f00dstamps]

Originally Posted by robnitro

is it 900 at 15 psi for the "perbar" or the other maf reading which is just mg/r (mg per stroke as vag com used to give us maf)???

If its per bar reading, example 900 at 15 psi, and you got 1800 for the other number, that means you are looking at the right reading. (1800/2 bar absolute=900 approx)
In that case yes, you probably have a boost leak because for 1 bar air, its around 500 mg/str

I am not sure the PIDs are working properly for my car. I get identical readings between the 2 gauges, perbar and mg/r. They are definitely not off by a factor of 2. After more use of the PIDs, they tend to show infinity signs at each increment as opposed to a number. Sometimes, they will show the correct numbers at the different intervals. I'm noticing that the numbers are higher now ~500 after I installed my race pipe.

[robnitro]

Per bar and the normal maf mg/r should be the same if you have no boost. With boost the mg/r will go higher than 500 of course, because it's directly tied to the maf kg/h or lb/hr mass flow.

Of course with EGR, you will get numbers lower than 500, because it's using some exhaust gas instead of 100% air. But at 50%+ load, EGR is basically off from what I see on my x5 driving.

The maf per bar is like "standardizing" it to 1 bar pressure.
It can also show a clogged intake, choking turbo, or saturated MAF where if you run high rpm/high boost the maf/bar reading will drop below 400. It was helpful for those TDI guys who had clogged intakes or stuck vanes, but we had to do the maf/bar by taking the log of boost/rpm and maf (vag com default is mg/r for maf) and doing per bar.

[f00dstamps]

Originally Posted by robnitro

Per bar and the normal maf mg/r should be the same if you have no boost. With boost the mg/r will go higher than 500 of course, because it's directly tied to the maf kg/h or lb/hr mass flow.

Of course with EGR, you will get numbers lower than 500, because it's using some exhaust gas instead of 100% air. But at 50%+ load, EGR is basically off from what I see on my x5 driving.

The maf per bar is like "standardizing" it to 1 bar pressure.
It can also show a clogged intake, choking turbo, or saturated MAF where if you run high rpm/high boost the maf/bar reading will drop below 400. It was helpful for those TDI guys who had clogged intakes or stuck vanes, but we had to do the maf/bar by taking the log of boost/rpm and maf (vag com default is mg/r for maf) and doing per bar.

Robnitro - I think I have the PIDs mostly sorted out. The mg/r reading is around ~500 at idle and goes up to 1200+ as the revs increase. The perbar reading was not referencing the MAF PID correctly; I got this fixed. At idle, I am getting ~500. Under light acceleration, it is dipping to 120-250. Under medium to high acceleration, it dips down to ~60.

Do I have bottleneck in my air supply?

[robnitro]

Wow 60 on perbar is very low! But the maf gets maxed out i read on our cars, it's mostly used for low or medium load egr metering.

What does lambda or afr say when you have that low like 60? It should not go much below 1 lambda or 14.7 afr. If so then you are really starving for air. But if you have so little air, you wouldn't be making power, does it feel weak or stumble? One time my TDI anti shudder valve (which is a throttle for shutdown) actuator broke free and would close at high boost causing tons of smoke and low power.

In that case check that your swirl flaps move ok (you might be able to feel the actuator rod under the intake manifold on drivers side of car iirc) , the egr is not stuck open and that the throttle by egr is not stuck and moves freely

[TDIwyse]

Originally Posted by robnitro

...But the maf gets maxed out i read on our cars, it's mostly used for low or medium load egr metering...

44.1 lb/min is the saturating point. You'll need to make some significant modifications to the vehicle to saturate the MAF.

[f00dstamps]

Originally Posted by robnitro

Wow 60 on perbar is very low! But the maf gets maxed out i read on our cars, it's mostly used for low or medium load egr metering.

What does lambda or afr say when you have that low like 60? It should not go much below 1 lambda or 14.7 afr. If so then you are really starving for air. But if you have so little air, you wouldn't be making power, does it feel weak or stumble? One time my TDI anti shudder valve (which is a throttle for shutdown) actuator broke free and would close at high boost causing tons of smoke and low power.

In that case check that your swirl flaps move ok (you might be able to feel the actuator rod under the intake manifold on drivers side of car iirc) , the egr is not stuck open and that the throttle by egr is not stuck and moves freely

While maintaining velocity at 30mph, I am getting perbar readings of 120-200. Under heavy load starting at 50mph and boosting to 34PSI with no downshift, I read as low as 39. Outside of a cold start situation, I have not seen my AFR drop lower than 14.5-14.7.

The car has power. Could it be producing more on the current setup? Maybe. Originally, I suspected a boost leak because my exhaust was indicating I have more than enough fuel. Now it appears that I do not have a [significant] boost leak but a bottleneck somewhere. I will look into the swirl flap actuator. Unfortunately, I do not have any readings pre-racepipe. My EGR was supposedly tuned out with my BPC tune. Now that I have the racepipe, is there anything EGR-related to troubleshoot?

Overall, I'm puzzled. AFR readings indicate that my car has a good balance at high load. MAF/RPM readings get as high as 1600 under high load (should it be even higher?). It seems like MAF/RPM should be higher by a factor of 6-8x to get the 39-60 perbar reading in the right range. The MAF is located directly after the airbox so do I have a restriction at my airbox or do I have a faulty MAF?

[robnitro]

What is the max lb/hr maf reading that you get at the high boost? I'm wondering why the numbers don't match up.

200 without egr seems low. I'll have to post my whole pids file, maybe something is wrong with the calculation in your case.


Tdiwyse, you're right about the maf.
Idle with no egr, no boost (aka 1 bar absolute) is around 2.3 lb/min.
29 psi boost for example is 3 bar absolute.
So ideally 3:1 ratio, and 4500/700rpm gives 6.5:1 by RPM.

So 3x 6.5x 2.3 would mean 44.85 lb/min for 29psig @4500 rpm
Lower rpm scales linearly.
For 44 lb/min at 3500 would be 44/((3500/700)x2.3. About 3.8 abs which is. 2.8x14.5=40psiG
4000 is saturated at 35 psiG

But in the other thread they said fueling is by lambda, so how could he be having excessive smoke? Do oxygen sensors fail and read optimistic?

[f00dstamps]

Just from memory earlier, I got 24 lbs/hr boosting close to 30psi. I am no where near saturation. Do I have a faulty MAF? Restriction at the air filter?

[robnitro]

It goes by rpm too because lbs by time is a total flow not like the /R. You recall the RPM?

30 psi about 2 bar- 3abs and 24 lbs/ would be around 2500 rpm. And it could even be 3000 rpm. But if you did this at 4k, it would be way low

Those calculations are an ideal max number, doesn't take into account hotter iat or higher emp.

[Irish335i]

I asked this in another thread but never got a response. Can't seem to find the answer anywhere on the Internet, either!

Can Torque Pro be programmed to display the current gear for a 2001 E90 335i 6AT? I was hoping to find the PID in this thread but it looks like just status of Park/Neutral and Drive/Reverse?

[DWR]

Originally Posted by robnitro

But in the other thread they said fueling is by lambda, so how could he be having excessive smoke? Do oxygen sensors fail and read optimistic?

Fueling by lambda is not meant to be taken literally. Oxygen sensors are used for "calibration". Calibration happens at several points, within an operating range narrower than the full operating range of the engine. DDE can control lambda by measuring air and controlling fuel, just like a gas engine.

Excessive smoke outside of the calibration range can happen in several ways. Suspect airflow first.

[DWR]

Originally Posted by f00dstamps

I have not seen my AFR drop lower than 14.5-14.7

Yeah, that'll make smoke.

[robnitro]

But if tuning was correct, you would have a time when a boost leak, etc would be implausible- vs the lambda reading. If it's that big of a deal, why would it be persistent for him?

So, either the tuning is short sighted and lazy- As I have seen in my "top notch tuner" TDI tune when I was retuning or something else awry.

Keep in mind that tuners sometimes are aiming for dyno numbers, without negative thoughts of bad conditions. It reminds me of the PLC programming at work, it's good code for when things are "normal" but becomes an issue if valves/pumps aren't perfect. Like tuning, the PLC is essentially a "dyno queen".

[f00dstamps]

I apologize about taking time to update my situation.

1. I figured out how to log the measurements I needed but I have not had a chance to analyze them or graph the results. More to come.

2. I encountered a modded WRX in Mexico and we decided to go from a 40mph roll. I let him do the honking and go before I mashed the throttle. It was no contest and I pretty much immediately overtook him and accelerated all the way up to 120mph. I smoked him (literally). The results were interesting but unfortunately I was not logging at the time. AFR went as low as 12.8. Boost went to ~34. MAF/RPM/Boost went to ~39. And interestingly, my MAF appeared to reach saturation at ~44 lbs/hr.

3. Robnitro - I do not recall the RPM but I do know I am running the test case starting in the 2k RPM range. I have to look analyze the logs to be sure but I am probably getting close to peak boost at 3k and generally let off by 4k.


I am curious if anyone else with a BPC II+ tune is encountering similar measurements. I wonder if my stock intake filter is too restrictive but I will be able to test this one my new intake arrives.

[DWR]

Originally Posted by f00dstamps

AFR went as low as 12.8. Boost went to ~34. MAF/RPM/Boost went to ~39. And interestingly, my MAF appeared to reach saturation at ~44 lbs/hr.
.

Are you running H20/Meth? If not, the AFR data makes no sense. Check the exhaust temps in either case.

An issue with BPC tunes can be diagnostics when problems occur. If you had some DTCs this might be resolved.

[f00dstamps]

Originally Posted by DWR

Are you running H20/Meth? If not, the AFR data makes no sense. Check the exhaust temps in either case.

An issue with BPC tunes can be diagnostics when problems occur. If you had some DTCs this might be resolved.

I am not running h20/meth. The peak EGT reading was ~1000-1200F during the Mexico run if I remember correct. I am reading ~350F under idle and <450F under normal operation.

What do you mean by DTCs?

[DWR]

Originally Posted by f00dstamps

I am not running h20/meth. The peak EGT reading was ~1000-1200F during the Mexico run if I remember correct. I am reading ~350F under idle and <450F under normal operation.

What do you mean by DTCs?

So, we can establish that the AFR reading is way off. Temps would have been through the roof (and maybe through a piston) at the AFRs you are reporting, with diesel only operation. My suggestion is to start by replacing the O2 sensor.
DTC = Diagnostic Trouble Code

[f00dstamps]

Originally Posted by DWR

So, we can establish that the AFR reading is way off. Temps would have been through the roof (and maybe through a piston) at the AFRs you are reporting, with diesel only operation. My suggestion is to start by replacing the O2 sensor.
DTC = Diagnostic Trouble Code

During cold start, my AFR reads 14.5 for a few minutes. After that it tops out at 29 unless I put a significant load on the engine. Would the 14.5 at cold start indicate the O2 sensor is working semi-correctly at least?

[robnitro]

During warmup you can see a really low AFR, especially if you left the throttle plate in - it pulls a -1 -2 psi vacuum for the post injections. So, leave out warmup and any tiny spikes.. steady state WOT , what is the lowest AFR that you see?

With TDI guys who run mafless, but map/speed density tunes there is low afr- big smoke on hard acceleration /transient throttle in low gears because of high EMP- vanes closed. Higher gears need less vanes closed- less EMP, so the map/rpm calculation is close to ideal.
That could be part of the issue if you got mafless.

If not mafless, maybe they made it "performance response", for extra smoke and temporarily low afr, you can get smoke to "help spool" the turbos. I put a lot in quotes cause if you compare a well done tune with one that does that, it's almost not a big deal to have a tiny bit of lag to not have to roll coal.
Only on trucks I saw that the single turbos that lag get a lot of help from rolling coal, and those guys upgrade to compound a lot. But a VW vnt, or BMW compound+vnt... why roll coal? It's either lazy or just like DWR said, they bypass some diags... so pretty much not much different than the TDI tuning which was highly valued.

A small story too, guy moved to germany. His highly rated (for here lol) tune failed TUV. He had some german tuner retune it, almost the same power but passed their strict testing!

Im not sure if there is a difference between the tuners here. Honestly, I have a friend who is trying to convince me to do it via galletto... If my dpf starts being a jerk, I will jump!