Ok gang... I'm going to share a few tidbit of information for advance OBDII tinkering.

 

If you happen to have a OBDLink or ELM327 tool you should be able to tag along here. I will have to give a bit of thanks to @Me78569 for getting me started with the Bluetooth terminal on Android. Once I had that I could directly communicate with the OBDLink and pass commands to it. So starting out I passed the command...

 

ATSP0

This basically tells the tool to communication with the detected protocol of the vehicle ours happens to be ISO 9141-2 protocol. After that I passed the command...

0100

Which happens to be PID Mode 01 with the PID 00 which tells the vehicle to report back which ODBII PID are available. It returns back.

41 00 98 3A 80 14
41 00 90 18 80 14

 

At this point the hexadecimal bytes you want are 98, 3A, 90, 18...

 

So now you need to take these 4 bytes on convert them to binary.

 

98 = 1001 1000

3A = 0011 1010

90 = 1001 0000

18 = 0001 1000

 

So now lay it all out in one long string. This is counting 20 hex (32 dec) from left to right.

 

1001 1000 0011 1010 1001 0000 0001 1000

 

So you have counting only the high bit (1's)...

 

01 - MIL Status Light

04 - Engine Load

05 - Coolant Temperature

(11) 0B - Manifold Pressure

(12) 0C - RPM

(13) 0D - MPH

(15) 0F - Intake Temperature

(17) 11 - APPS Sensor

(20) 14 (Unknown yet)

(28) 1C - OBD Compliance should report 05 hex.

(29) 1D - (Unknown yet)

 

NOTE: (number) is decimal... Just for the human side for counting placement. ECM/PCM use the hexadecimal values only.

 

Now if you want to add any of these as a custom gauge.

 

Module/Header: 486

OBD Mode: 01

PID Number: (Any of the above will work use only the Hex number not the decimal)

Priority: Leave on High

Equation: Look it up on Wikipedia at https://en.wikipedia.org/wiki/OBD-II_PIDs

 

 

 

 

Edited May 27, 20168 yr by Mopar1973Man

Mine clearly reports A as 1 kpa. I've confirmed it with quite a bit of driving around with live data. I guess other years report differently?

On 2/3/2017 at 5:38 PM, SpaceHiker said:

Well, since I've taken it upon myself today to solve the mystery of my truck's poor performance on 2-stroke oil (see cumminsforum), as a side effect I solved the mystery of the boost formula.

 

The correct boost formula that works 100% accurately at any elevation is: (A/6.8947)-14.6

 

This means that in any OBD software, you need to add a custom PID for boost. For the mode and pid, enter 010b or 01 0b (depending on your software's format). For the minimum value enter 0, for maximum value enter 100 or 60 or whatever you want (22 suffices for my stock truck lol). For equation, enter the above formula: (A/6.8947)-14.6

Then for decimal point precision, just use 1 decimal point.

 

This formula does not depend on atmospheric pressure at all. And in fact, the whole discussion about atmospheric pressure is completely overblown because it really only concerns our trucks when they are at idle. You have to keep in mind the function of a turbocharger. It is by it's nature a perfect altitude compensator and will always try to achieve a certain equilibrium within it's mechanical limits. This means that as soon as we begin applying fuel with a press of the throttle, intake pressure comes up above standard atmospheric pressure anyway. It just takes slightly longer at 10,000 feet than it does at 2,000 feet.

 

For the above reason, and since I'm at 9,240 feet, I see my boost sit at 0.0 for a little while before it starts coming up. That time where it's at 0.0 is when the turbo is reaching 14.6psi. It's a very short period of time, but it is noticeable at my elevation (lasts about 2 seconds after applying throttle). My mechanical boost gauge shows the same thing.

 

Hopefully that clears up some of the issues that have been bubbling in this thread for a while. Just keep in mind that my truck is a 98.5, I don't know if the newer trucks report a different data format on 010b, but I can't see why they would.

I'll give this a try next time I'm in my 02 and see if it works. Thanks! 

You are reading boost over the sci bus I am reading it over the canbus port under the hood.  

 

The canbus port under the hood reports boost as .5 kpa per A 

 

It's interesting to me that the sci bus reports it differently. 

(A/6.8947)-14.6  tried this formula and at idle, my gage was sitting at 14.6. So I subtracted another 14.6 and it set it on 0 but seemed to kind of track with my gage up to about 15-20 psi and it wouldn't go any higher. not sure what's up with that.

 

boost fooling from the ez.  Remember the obdlink is showing you what the ECM is seeing, the Edge is limiting what hte ecm sees.

Edited February 7, 20178 yr by Me78569

Little change of direction here. I would like to use my obdlink dongle on  my 3 vehicles. Is there any way to save a vehicle in the vehicle editor so I don't have to re-enter everything every time I switch cars? Like download the app 3 times and have one for each car or something like that?

No need. The app will reconize the vehicle and rehook to its own profile. I've got my 96 and 02 Dodge.

Edited February 22, 20178 yr by Mopar1973Man

1 hour ago, Mopar1973Man said:

No need. The app will reconize the vehicle and rehook to its own profile. I've got my 96 and 02 Dodge.

Is there something special that needs to be turned on? Mine doesn't do that.

As far as I've seen between my two trucks once you've saved the first profile for each one it automatically picks up the profile the truck and uses it. I'll double check again and see if there is a bug or something changed. I'll be a few days before I can test this. 

MIne also remembers the vehicle.  I didn't have to turn anything on.  The only time I had to re-enter my vehicles information is when I removed and then reinstalled the app on my phone.

Hmmmm. Today I took it out of the Tahoe and put it in my 300M. No VIN or anything came up for the 300M. It knew I changed vehicles because it told me to edit my vehicle in the editor, but did not display the VIN or fill in any of the info that comes along with it like it did the Tahoe. When I put it in there it had most of the info filled out just by reading the vin. like engine size etc. I'll have to put it back min the Tahoe and see if it changes but it appears I must be missing something.

I have run mine on 4 vehicles and it only recognized the VIN on my wife's Honda Odyssey van and my sister in laws Toyota Sienna van. All the others load up the vin blank. I have yet to fill them in but all the tools work and it will connect to each vehicle If you label each one. You should just plug it in, wifi should load up automatically although I check it first,then open app and push connect button at the bottom of app screen. I don't have it set up anymore automatic than that because I want physically see my vehicle profile load when I push connect. I am running on iphone7. It's a bit different than android I think. 

After you enter the stuff manually for the vehicle editor that doesn't load your vehicle for the first time, it should load from that point on when you switch vehicles. 

On 2/23/2017 at 4:47 AM, woodtrucker said:

I have run mine on 4 vehicles and it only recognized the VIN on my wife's Honda Odyssey van and my sister in laws Toyota Sienna van. All the others load up the vin blank. I have yet to fill them in but all the tools work and it will connect to each vehicle If you label each one. You should just plug it in, wifi should load up automatically although I check it first,then open app and push connect button at the bottom of app screen. I don't have it set up anymore automatic than that because I want physically see my vehicle profile load when I push connect. I am running on iphone7. It's a bit different than android I think. 

After you enter the stuff manually for the vehicle editor that doesn't load your vehicle for the first time, it should load from that point on when you switch vehicles. 

 

It depends on the software you are using. If you are using the torque pro app for android, it allows you to create and save a custom live data profile for each vehicle. It does not automatically switch over based on the vehicle it's connected to. You have to change the profile manually, but the procedure is obvious. 

 

Other software will behave differently. You might need to switch to a different app.

I think it's working now, but as said above it doesn't load the VIN for the truck but it recognizes each vehicle. I also noticed there are 3 pages of gauges and I will use 1 page for each vehicle so I don't have to change them every time I switch. What's this torque pro thing and where do you get it?

Go out on google play you'll see the OBD apps available you can use any app you want for OBDlink if you wish but the other problem is you most likely going to have to pay for other apps. 

 

https://play.google.com/store/apps/details?id=org.prowl.torquefree&hl=en

 

https://play.google.com/store/apps/details?id=com.palmerperformance.DashCommand&hl=en

 

https://play.google.com/store/apps/developer?id=Palmer Performance Engineering&hl=en

 

https://play.google.com/store/apps/developer?id=Ian Hawkins&hl=en

On ‎3‎/‎3‎/‎2017 at 8:41 AM, Mopar1973Man said:

Go out on google play you'll see the OBD apps available you can use any app you want for OBDlink if you wish but the other problem is you most likely going to have to pay for other apps. 

 

https://play.google.com/store/apps/details?id=org.prowl.torquefree&hl=en

 

https://play.google.com/store/apps/details?id=com.palmerperformance.DashCommand&hl=en

 

https://play.google.com/store/apps/developer?id=Palmer Performance Engineering&hl=en

 

https://play.google.com/store/apps/developer?id=Ian Hawkins&hl=en

Thank you. Hey Mike, can you post a screen shot again of what the values are supposed to be. I can't seem to find it. Also, how do you know what the values should be for other vehicles?

3 hours ago, dave110 said:

Thank you. Hey Mike, can you post a screen shot again of what the values are supposed to be. I can't seem to find it. Also, how do you know what the values should be for other vehicles?

 

 

Here you go... My whole article on it.

 

On ‎3‎/‎5‎/‎2017 at 4:26 PM, Mopar1973Man said:

 

Here you go... My whole article on it.

 

Great! One suggestion. Somewhere you posted a link for a nifty calculator to figure out the offset for the vol. efficiency. That would be a good addition to this article along with an explanation on which number goes where.

1 hour ago, dave110 said:

Great! One suggestion. Somewhere you posted a link for a nifty calculator to figure out the offset for the vol. efficiency. That would be a good addition to this article along with an explanation on which number goes where.

 

 

I'll try to get the write up done... 

Maybe a little off topic here but I reckon it'll get the attention of the right folks here...I just completed my Cummins swap and I'm wiring in the dodge pcm to get through my emissions test. My question for you dodge can junkies is can my Allison tcm and the dodge pcm share the same obd plug? I have already checked and the same pins are used although I am not able to find out if the same pins are being used for the same functions or if that even matters. If they are both hooked up to the same obd will the emissions control equipment initiate communication with the pcm, and the efilive autocal I use to tune my transmission talk to the tcm, or will everything just end up a jumbled mess? I do know my tcm speaks j1939 but I'm not sure what protocol the autocal uses to communicate with the tcm. You guys will know far better than I what protocol is used by the dodge pcm at the obd plug. What do you think?