I started to write up a user guide some time ago and was sidetracked. Got the intro written so I am pasting it below. I'll try to get some simple instructions written up that will cover your questions sometime today. In the meantime, please start your own new thread if you would like specific help with your issues.

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Intro:

Car Gauge Pro is an app for Android that functions as an OBD2 scanner. The following information is specific for using Car Gauge Pro v.3.66.26 on a 2001 Chevrolet Blazer. As far as I know this should be the same for all 1996-2004 Blazers and S10s. Like-year GM vehicles with 4.3 or 5.7 Vortec engines should be very similar.

Car Gauge Pro seems to have a very complete set of Enhanced GM PIDS for Powertrain. It does In fact include the PID for Camshaft Sensor Retard (CMP Retard) used for GM Vortec 4.3 and 5.7 liter engines (PIDs are Parameter IDs that are used to request data from the vehicle PCM). Having all of these enhanced GM PIDs in software or scanners under $150 is very rare in my experience. Indeed, Torque Pro (a favorite of Android users) includes many of the GM Enhanced PIDs but fails toprovide the one for Cam Sensor Retard (which is typically used for checking/verifying distributor rotor position during misfire diagnosis, or for those of us who want everything to be just right). It is available in the Car Gauge Pro PID list as “CMP Retard” (note use the PID with single asterick). Still Torque Pro has a very nice user interface and some nice features that Car Gauge Pro does not provide. I think of these two apps as complimentary software and the price for both is certainly right! $8.95 for Car Gauge Pro and $4.95 for TorquePro. Both of these are installed on pretty much any fairly recent Android Phone or Tablet, but to connect with your vehicle there needs to be an OBD2 adapter.

Android OBD2 apps are usually interfaced with the vehicle computer wirelessly through their Bluetooth connection using a small (traditionally ELM327) OBD2 adapter plugged into the OBD2 connector. There is an expensive version of this adapter that is known to give highest refresh rates and reliability (OBDLinkMX), but they cost about $90. Fortunately there is one inexpensive “Chinese Clone” that has been shown to give excellent refresh rates as well as reliable connectivity. This is the Bluetooth OBD2 Adapter from BAFX as sold on Amazon for $23.99. Note the 5000+ reviews and 4.5 star rating – I believe both of these are real. I have had both OBD2 adapters connected to my Blazer and the only difference I have seen is that the OBDLinkMX obtained around 30 scans/sec while the BAFX gave around 20 scan/sec. Both are adequately fast and do exactly the same things on the Blazer (no more no less). In contrast, a $10 Bluetooth OBD2 adapter from Amazon that I tried gave only 3 scans/sec, and this made it virtually un-useable for live data where more than one PID was being monitored at the same time. This is why I think the BAFX device gives the most value, and is definitely the one to choose for use with 1996-2004 Blazers and S10s.

There seem to be three common complaints about Car GaugePro.

1) User interface is not intuitive and is difficultto learn how to do things

2) There are no instructions for using it

3) Says it requires OBDLinkMX /Can’t Connect, or simply does nothing when a particular function is selected.

The first two I am attempting to help with through these instructions (at least for Blazers/S10s). The last complaint I will address now.

You need to understand that Car Gauge Pro has unfiltered lists of Modules and PIDs for different vehicle makes. Just because a module exists under GM, that doesn’t mean that you can connect to all of the 36 listed modules with every GM vehicle, nor does it mean that you can do all things within a module. Your vehicle system has to be compatible, and there is no guidance given regarding this. You might get a “requires OBDLinkMX” message, but know for the 2001Blazer that putting an OBDLinkMX in place of the BAFX will not make the function work. I know this as I have tried. Only difference is the message changes to “failed to connect”.

The only truly functional module I have found to connect to in Car Gauge Pro for the 1996-2004 Blazer is the Powertrain module, but that in itself (ability to do cam sensor retard) is reason enough to buy this app. I should note that in my 2008 Ford, additional modules like SIR and ABS seem to be fully functional, so you mayfind a lot of additional functionality as well on different vehicles. It really was designed for late model Fordand Nissan, so additional functionality is to be expected with those makes. Car Gauge Pro is even known to do injector buzz tests on Ford diesels.

As an aside, I have been told by the maker of Car Gauge Pro that it does not support any enhanced GM PIDs for CAN Bus vehicles. This would be most 2006+ GM vehicles. To connect to the PCM on my 2006 G6 (firstyear of CAN protocol for GM), I have to connect as OBD2 generic – but it doeswork for basic OBD2 functions and data. Torque Pro cannot connect at all to this vehicle as I have not figured out how to select OBD2 generic in that app – it tends to be more automatic. More expensive software with USB connection like ScanXL Pro and HP Tuners have zero problems connecting to my G6 . Your experience may vary with your late model GM vehicle. I have not tried any GM vehicles newer than my 2006 G6.

That said, let’s get into installing and using the Car GaugePro app with the BAFX Bluetooth OBD2 Adapter to display CMP Retard on a 2001 Blazer.

 

After the software has connected to the vehicle, the functions used to clear DTC's appear in the Diagnostic menu.

 

Thanks to your direction on this, I was able to do my distributor swap easily and got it to about 0.5 degrees. Thanks! In fact I have emulated many of the gauges you showed.

In playing with this app, I have noticed it does have transfer case ratio and it does pull data which changes from 0.2 to 0.5. Do you by any chance know if this is accurate data? I am running this on an 01 Bravada and have had issues over time with the dependability of the Smartrack system, and if something like this shows usable data it would be huge.

 

You are welcome!

I have never tried transfer case ratio (which is found in the Powertrain Module), or understand what it represents.

As an aside, I could never get the GM transfer case module in Car Gauge Pro to work with my 2001 4-button Blazer, even though it appeared to connect with the TCCM. I have connected and read/cleared codes with my 4-button TCCM by using an OBD2 terminal in ScanXLPro and typing in the binary. I imagine it would work with any valid terminal application for the Android. I can tell you what to type to request codes and how to decipher what it gives back but you would have to get a terminal app working on your Android and connected with the Bluetooth. I know of no way to read actual transfer case data - only read/clear codes.

 

The gauge I was showing was actually working in the Powertrain Module. Not sure if the data is pulling from anything relevant, but I did get a variance in the reading as I drove. May be nothing, but with the lack of documentation for the app, I didn't know if you ran across anything like this.

 

I am not familiar with ScanXLPro...need to check it out. If you can provide that data on how to request the codes, I would LOVE to try it.

I have done as much digging as I can, and have emailed the developer on the Car Gauge Pro app to ask about the Transfer Case Ratio percentage. Once I get a response I will share that. But thanks again for all your work on providing data for this app. If not for this thread I would have taken my bravada in and had the distributor swapped by someone with the tool.

 

Quick and Dirty How to make Dashboard Screens

* Connect/GM Powertrain/Full Auto Scan/OBDII/select the shown address
* Let software scan the available PIDs
* Save PIDlist to a filename of your choice.

Now you don't have to be connected to the vehicle to do the rest so disconnect and go back into the house.

* Connect/GM Powertrain/no scan/import PIDs /import from file/select your PIDlistfilename

To make a CMP Retard gauge like mine

Select Dashboard

* go to a blank page
* tap in top right corner of the screen
* select add gauge
* select CMP Retard* from available PID list
* Check Digital
* Select Add

Then to make a misfire counter like mine

* select Misfire #1 from available PID list
* Select Add

Repeat last steps again for each of the other desired misfire counters

When done hit your back button on your phone and the Add gauge screen will disappear.

Press on a gauge you wish to move until Display config appears.

* select Drag and Move
* Drag the gauge to the position where you want the gauge on the screen.

Repeat until you have the gauges where you want them on the screen.

To save your profile, touch the top right of your screen, select Guage profile/save/tell it where to store it/type in a name/hit save.

Now you can select from multiple gauge profiles by name by touching the top right of the screen, selecting gauge profile, and recalling the file.

 

Post 4 of the following thread expains the hexadecimal codes sent/received for checking/clearing codes on NP8 4WD using a ODB2 terminal. It's not that you need to have ScanXLPro and a laptop - it's just that ScanXLPro included an OBD2 terminal that I could use. Should be able to find an Android app that will do this through your bluetooth device. There are tons of free OBD2 terminal apps in the Google Play Store. Anything made by OBD Scantech is the same guy that made Car Gauge Pro. I do not know if the all wheel drive is the same as NP8 4-button, but I see no reason for it to be different for the purpose of checking/clearing codes.
https://blazerforum.com/forum/2nd-ge...-blazer-89044/

If you are interested in my foray into 4WD diagnosis, that is here
https://blazerforum.com/forum/2nd-ge...or-lock-89046/

 

Good stuff. Just went through the 4WD diagnosis thread. My Bravada is on its second encoder motor (the one I put in last year started blowing fuses so I put a new one in it but have had no weather to really test it out under severe load - yes I just threw the part at it but it was under warranty so cost me nothing). I get the Service AWD light when i first start up and then it shuts off like it should. This is where I wish I had a Blazer instead to test the buttons...like your Blazer, this Bravada is super nice and I am the second owner (my father in law was the first), but the whole SmartTrak system is maddening.

Regardless I am going to find an OBD2 terminal program and see what I come up with. I have long suspected something with the TCCM on mine, and your journey seems to confirm that for me. I'll see what I can find and then go from there.

 

ntjoe, Keep in mind that RPO code NP8 is a 2 speed, Auto transfer case, (NV236). Your Bravada has either RPO code NP3 or NP4 which are single speed, SmartTrak, transfer cases, (NV136). Diagnostics are similar, but not the same.