Who wants an Arduino-based Aux Instrument Panel?

Axiom

Mike from Florida Van Man
Check the SD card for a complete list of the codes found. Even if they don’t fit into the scroll box, they are written to the DTC file on the chip.

My understanding is that, once erased, a “present” code will reappear as soon as the relevant test is repeated by the ECU and the fault is verified. Decoding the “status byte” (see post a few pages back) may help understand the van’s behaviour?

-dave
I'll check the SD card today! But from what I could see in the list, it looks like the usual assortment of spaghetti codes that are thrown when you have a low battery and try to start. I plugged my Autel BT scanner in and successfully cleared all the codes, none have come back.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
I can only speak to the testing I did yanking wires to induce and clear faults on my own van.
I was able to clear the “stored” status of all faults, but they did remain pending if I hadn’t corrected the problem.
Once the wires were plugged back in I had no issues clearing “stored” or “pending” faults.
This worked with either module.
So I am confused that you couldn’t clear anything from your van?

-dave
 

calbiker

Well-known member
Don't know how much effort you want to invest, but there is some investigative work that can be done. It entails building a two transistor sniffer circuit to view communication between your AP200 scanner and the vehicle. You need a OBD Y-cable and an Arduino processor, both can be purchased from ebay.

Details should be here.

https://sprinter-source.com/forum/showthread.php?t=47542&highlight=cracking


Is this a "completely incompatible" kind of thing or a "currently incompatible" kind of thing? If you think it might be possible to support the OM612's I'd be happy to be a guinea pig and contribute any way I can. Admittedly I don't know much about vehicle diagnostics but I am a software developer by trade... otherwise, might have to return it.
 

Gvnclk

New member
I received my unit a few weeks ago and it's been great but so far the fuel consumption has not shown any data. Initially I thought it may need time to calibrate but I have gone through 2 tanks of fuel and it's still blank. Any ideas what the issue could be?
 

Axiom

Mike from Florida Van Man
I received my unit a few weeks ago and it's been great but so far the fuel consumption has not shown any data. Initially I thought it may need time to calibrate but I have gone through 2 tanks of fuel and it's still blank. Any ideas what the issue could be?
Are you able to see it on the second page? Sometimes mine will show 0mpg on the main page and switching to the second page let's me see the data. Switching back should then have it populate on the first page.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
The fuel economy calculation requires the MAF and O2 sensor voltage, so a lack of fuel economy readout may point to a sensor problem? My readout sits on zero for a few (five?) minutes while the O2 sensor heats up (normal?) but is then quite stable, and within 10% of long-term consumption.

-dave

added:
I sent some info out today to help start the cracking and adapting of the program to interpret 2003 OM-612 data, but since the OM-612 doesn’t have an O2 sensor, I’m not sure that I’ll be able to provide a meaningful fuel economy value without first cracking the ECM’s software lockout challenge/response algorithm.
 
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cian128

Member
The fuel economy calculation requires the MAF and O2 sensor voltage, so a lack of fuel economy readout may point to a sensor problem? My readout sits on zero for a few (five?) minutes while the O2 sensor heats up (normal?) but is then quite stable, and within 10% of long-term consumption.

-dave

added:
I sent some info out today to help start the cracking and adapting of the program to interpret 2003 OM-612 data, but since the OM-612 doesn’t have an O2 sensor, I’m not sure that I’ll be able to provide a meaningful fuel economy value without first cracking the ECM’s software lockout challenge/response algorithm.
Does mph/gph end up a bogus number?
 

Nautamaran

2004 140” HRC 2500 (Crewed)
As I explained above, the mph is derived from the calculated L/100km, but while stationary the conversion from the metric litres per hour does NOT convert to gallons per hour, and jumps to 120 mpg standing still... oops.
But I’ve found my displayed L/100km to be representative of my average consumption rate. It’s hard to be sure of much during city driving, but on longer highway drives I have purchased within a few percent of what the box calculated I had burned (the small number in the middle of the “details” page counts calculated litres (gallons) burned) and the instantaneous fuel economy seems to believably reflect hill climbs, head-winds, reduced speed, etc. enough to guide my driving strategy.

-dave
 

Axiom

Mike from Florida Van Man
I let it guide my driving strategy, and wound up doing just about 600 miles on a tank (586 miles by the time I found a station, with it showing 1 gallon of fuel left). That's insane when you consider I STILL haven't found the source of my engine clack, I'll take it. Thanks for this wonderful device again Nauta ;) :thumbup:

According to Fuelly, my new average is up to 23.8mpg
 

Nautamaran

2004 140” HRC 2500 (Crewed)
I imagine that service station was a welcome sight!?

The “Fuel in Tank” number (top right, details page) is straight from the ECM. The data value ranges from 0-100 litres and I convert it to US gallons for the display.
The ECM gets it from the IC module via canbus. The IC determines the tank level by interpreting the variable resistance that it measures across the tank sensor circuit, which changes according to the floating bobber on the end of a metal rod. There’s a post in the “Crackinng the K-Line” thread tabling sensor resistance as I did a tank fill... the sensor flat-lines when it floats up against the tank top, so the IC is blind to the last 10 or 15 litres added, which is why the fuel gauge stays pinned at Full for the first few gallons burned. I expect it’s equally blind to the dregs once the sensor is sitting on the bottom of the tank, but I’ve never ventured that low - I try to avoid drawing it down too far since I don’t know how low fuel level affects the cooling performance of the fuel system... I keep a log and typically fill at 400 mile intervals, though I usually need a break long before the van does...

-dave
 

Gvnclk

New member
The fuel economy calculation requires the MAF and O2 sensor voltage, so a lack of fuel economy readout may point to a sensor problem? My readout sits on zero for a few (five?) minutes while the O2 sensor heats up (normal?) but is then quite stable, and within 10% of long-term consumption.

-dave

added:
I sent some info out today to help start the cracking and adapting of the program to interpret 2003 OM-612 data, but since the OM-612 doesn’t have an O2 sensor, I’m not sure that I’ll be able to provide a meaningful fuel economy value without first cracking the ECM’s software lockout challenge/response algorithm.


I haven't been able to read it on any of the pages. And recently did a 5 hr drive so it's not about the distance.

It could be a sensor issue, I don't get any engines codes but have wondered if I have an issues with MAF or O2 for sometime. I guess it's time to replace them both and see if that helps.


Sent from my iPhone using Tapatalk
 
I love this little gadget. Is there a way down the line to be able to read trans fluid level? What’s the difficultly level that comes with that?


Sent from my iPhone using Tapatalk
 

Nautamaran

2004 140” HRC 2500 (Crewed)
Are there instructions that come with it? Or, do I just plug it in?
I suppose I should provide a set of instructions, but it really is intended to be a “plug it in and go” item.

A few things you may not readily discover:

- when tapping the screen, you need to hold down until the spot glows. The touch screen is resistive and doesn’t have a hardware interrupt, so needs a moment’s patience...

- tapping the numbers on the first “Driving” page toggles the displayed (and logged) unit for the group of items. For example, tapping Boost swaps between psi and kPa, taking the rail pressure units with it, and the temperatures all toggle together between F to C.

- the speed calibration number on the “Setup” page is a multiplier, not an offset, and scales the speed values displayed. The units ship with a calibration of 1.040, which correct for slightly low speed readings from my van’s wheel speed sensors. You can measure your true speed with a GPS or time a measured mile, then adjust this calibration to correct the displayed Speed for your van’s quirks (such as non-stock wheels or tire size)

- the Log File will only enable when a microSD is present before you power on the unit. The log writes about every five seconds on the three data screens, or about every two on the Setup screen. But the log is only committed (sync’ed) every 30 seconds or when logging is switched back off (“disabled” selected), so you will typically loose the last few entries when the unit looses power when you turn off the key. The Arduino platform doesn’t easily support detection of a loss of power, so I can’t gracefully close the log file when you turn off the key. The 30 second interval is a compromise, since the log takes very little time to write to the SD card (most of the two seconds is spent gathering data over the k-line), but a sync operation takes about half a second, which is a noticeable pause in the already slow screen refresh.

- a new log file is started each day, and subsequent driving data is append to the daily file. A header in the file explains the data contained in these entries.
- when reading fault codes they are appended to a single fault code log. Each logged code is accompanied by the “details” data. This contains the mileage, fault counter, fault sub-code, etc., though I don’t yet know how to decode this raw data.

A final caution: NEVER use a Y-connector to connect multiple scan tools to the Sprinter data port. The K-Line does not support multiple testers, since each tester assumes it is in control and supplies the electrical power for the communications wire. The vehicle’s modules must handle the total power connected, so multiple Test Tools can overload them. (in the later CANBUS systems the comms lines are powered by the vehicle, so adding multiple test nodes is electrically safe)

-dave
 
I love this little gadget. Is there a way down the line to be able to read trans fluid level? What’s the difficultly level that comes with that?


Sent from my iPhone using Tapatalk
I haven't plugged mine in yet. My dream would be front brake temp. It would require installing a sensor, but would be helpful for mountains. My sprinter is in the form of a small motorhome, so it's at GVWR and drives like a pig.
 
I suppose I should provide a set of instructions, but it really is intended to be a “plug it in and go” item.

A few things you may not readily discover:

- when tapping the screen, you need to hold down until the spot glows. The touch screen is resistive and doesn’t have a hardware interrupt, so needs a moment’s patience...

- tapping the numbers on the first “Driving” page toggles the displayed (and logged) unit for the group of items. For example, tapping Boost swaps between psi and kPa, taking the rail pressure units with it, and the temperatures all toggle together between F to C.

- the speed calibration number on the “Setup” page is a multiplier, not an offset, and scales the speed values displayed. The units ship with a calibration of 1.040, which correct for slightly low speed readings from my van’s wheel speed sensors. You can measure your true speed with a GPS or time a measured mile, then adjust this calibration to correct the displayed Speed for your van’s quirks (such as non-stock wheels or tire size)

- the Log File will only enable when a microSD is present before you power on the unit. The log writes about every five seconds on the three data screens, or about every two on the Setup screen. But the log is only committed (sync’ed) every 30 seconds or when logging is switched back off (“disabled” selected), so you will typically loose the last few entries when the unit looses power when you turn off the key. The Arduino platform doesn’t easily support detection of a loss of power, so I can’t gracefully close the log file when you turn off the key. The 30 second interval is a compromise, since the log takes very little time to write to the SD card (most of the two seconds is spent gathering data over the k-line), but a sync operation takes about half a second, which is a noticeable pause in the already slow screen refresh.

- a new log file is started each day, and subsequent driving data is append to the daily file. A header in the file explains the data contained in these entries.
- when reading fault codes they are appended to a single fault code log. Each logged code is accompanied by the “details” data. This contains the mileage, fault counter, fault sub-code, etc., though I don’t yet know how to decode this raw data.

A final caution: NEVER use a Y-connector to connect multiple scan tools to the Sprinter data port. The K-Line does not support multiple testers, since each tester assumes it is in control and supplies the electrical power for the communications wire. The vehicle’s modules must handle the total power connected, so multiple Test Tools can overload them. (in the later CANBUS systems the comms lines are powered by the vehicle, so adding multiple test nodes is electrically safe)

-dave
Without this warning, I would certainly have plugged my icarsoft II into the other port, since I have a Y connector. Thanks for the heads up. :thumbup:
 

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