OK, so you want to roll your own version of GM's OnStar, Subaru's StarLink, Ford's SYNC and so on.

Let's assume getting the information you need while in the car is easy and that the hard part is getting that info onto the internet.

I say it's easy because very cheap OBD readers and GPS units are readily available. Neither of these are smart enough to totalize information and track maintenance intervals but the OBD would give you enough access to information that should - if you can get at it - give enough information for a remote app to compute what to do. Be aware that not all cars use the same OBD protocols. I'm using the term generically, but there are other systems and they're not compatible. The device you use has to work for the vehicle you have.

One solution that you might implement quickly is to build a smartphone into the car running a custom app to do the monitoring and calculations, and then send the info to the web. I've used my iPhone to talk to my OBD reader but I don't think I can be on the internet at the same time. My OBD reader is wifi, and when I'm connected to its wifi network I cannot also be on cellular. Many of these OBD devices are bluetooth and perhaps this would allow simultaneous connection. You might be able to have the phone switch from the car's network to the internet, but I don't think the OS will allow an app to change the data network without user intervention, which I assume you don't want.

This interim solution (interim because I assume you don't want a cellphone in each car) requires that each vehicle has a paid data service plan. Any solution will require this if you want continuous access to every vehicle. Custom hardware to replace the cellphone cannot solve the problem of access to data service. If you can live with intermittent access, you could have the cars "check in" anytime they are in range of free wifi spots such as your offices, all McDonalds, and so on.

Assuming you can solve that problem of getting data service, then you just need a server to synchronize the data to. Many apps synchronize user data back to their home servers, so I think you can take as given that you can do this without too much trouble. Once the data is on the server, you'll need an app that can read the databases, search for 'events' requiring attention, send notifications and so on. That's a lot of programming but I don't see any obvious hurdles beyond the hard work.

Fabulas thinking man!!!
What if I developed a dedicated embedded system which will take raw data from OBD port do all computing part attached with gps(for providing location information) and GSM/GPRS MODULE/WIFI Module for internet connectivity and will send information to cloud.
I can also connect a small display in vehicle also and at same time it will be stored on cloud.
Also by using such display we can show more accurate information digitally.

 

Years ago ELM327 was open source. Just because the open source ElmScan source code for the ELM327 isn’t available on line and I have it, here it is. The output was text strings. They weren't obvious but you could sort it out if really motivated. The needed alld42.dll is in the zip folder, put it in C:\windows\system32.
This is the ELM website with data sheets & technical info.
http://www.elmelectronics.com/obdic.html
https://www.elmelectronics.com/wp-content/uploads/2016/07/ELM327DSF.pdf

This is the one I got with USB and is compatible with that source code.USB OBD2 OBDII Code Readers Scan Tools Auto Diagnostic Scanner Car Diagnostic Tool Auto Scan Check Engine Light...
The newest ones are Bluetooth nowProfessional Diagnostic Tool OBD2 OBD-II ELM327 ELM 327 V1.5 Bluetooth Car Diagnostic Interface Scanner Works...
And WiFiELM327 WIFI Wireless ELM327 OBD2 OBDII Auto Diagnostic Scanner Tool Adapter for Smartphone / PC / iOS / iPhone...
All less than $20.00

Info here OBD-II PIDs - Wikipedia, the free encyclopedia

Thank You so much...
At this time I am not much friendly with this but soon I will get back to you.
I studing all material you provided and I belive this is very helpfull for me.
Thanks a lot...

 

This https://atmosphere.anaren.com/wiki/Main_Page could be a perfect platform too. There's a better page somewhere to start.

 

If you get some resources about this project please let me know I would like to take look of that.
Please suggest by using same resources how I can add more features to the project.

 

This https://atmosphere.anaren.com/wiki/Main_Page could be a perfect platform too. There's a better page somewhere to start.

Thanks
It's looking quite interactive and graphical based. I would love to work on this.

 

This is something I tried to figure out what I wanted to do...

 

You've captured much of what the commercial solutions provide, although I think they use satellite communication instead of cell technology. I'm not sure about that and may have it confused with Sirius. But both Subaru and GM have "star" in the name of their service. To me that implies satellite. That doesn't mean your plan won't work. You'll just need to handle occasional losses of service.

 

You've captured much of what the commercial solutions provide, although I think they use satellite communication instead of cell technology. I'm not sure about that and may have it confused with Sirius. But both Subaru and GM have "star" in the name of their service. To me that implies satellite. That doesn't mean your plan won't work. You'll just need to handle occasional losses of service.

I am usign gprs module to give internet connectivity. I can also use wifi but it's quite unsecure so I preffered gprs module.
Do you have any other best option to provide internet connectivity which is secure, faster, cheaper and compact.
I am providing internet connectivity to store the collected data from car on cloud continuously. and this data will be analyzed and result will be presented through android app connected to same cloud.
The results may include showing various parameters like engine temperature, speed, emission rate, fuel status.
Detecting the faults and alerting to the user as well as send this health report to the garage based on analysing users preferance and schedule maintainance automatically.
Generate performance information and suggest ways to improve.