Onboard diagnostic system help needed

[RK NAIR]

Hi all ,

i am in need of a tech assistance for building an Onboard diagnostic system to monitor the diesel engine using lap top or some other mehtod.
I had searched through google to find out a circuit for this , but unfortunatly there is no cicuit avilable.

please help me to build this project including the sensor portion . the following things are needed
circuit diagram
software to run the same
sensor circuit

This will monitor the engine rpm. crank case temp, ........and lot

 

[evandude]

so basically you want us to do your project FOR you? doesn't sound like much of a project to me :lol:

 

[ante]

Nair,

Almost all modern diesel engines have this built in but you sometimes need a code for the canbus system to “get inside”. Some of these can even alter some variables to tune the engine. What make and model is your engine?

 

[RK NAIR]

Re OBD II

Nair,

Almost all modern diesel engines have this built in but you sometimes need a code for the canbus system to “get inside”. Some of these can even alter some variables to tune the engine. What make and model is your engine?

Dear Ante,

Thanks for your positive response. What you said is exactly right , but in india none of the vehicle doesnt have this OBD II system. Because the rule is not come in india so far.

As you said , is it possible to build a common system to monitor any of the engine? If so please let me know the same.

This is for my workshop , different types of engines will come for service.But most of the engines are LOMBARDINI diesel - 2cyl & 4Cyl - 4 strock engines.

I would like to know from your side, what are function this OBD will do, which is already available along with the vehicles in Europe.

 

[RK NAIR]

re OBD

so basically you want us to do your project FOR you? doesn't sound like much of a project to me :lol:

Dear Evandude,

I have asked for a helping hand from the experience chabs, that doesn't mean that you have to do one project for me. If you took it in that corner , iam realy sorry"""

 

[williB]

the On Board Diagnostics website-- These service codes show you such things as knock sensor operation, FI pulse width, ignition voltage, individual cylinder misfires, transmission shift points and ABS brake condition

i dont know what the F1 pulse width is
BUT i imagin it has to do with spark..so you are going to need a spark sensor circuit..one of those things that clamps on the spark wire will do...

 

[tansis]

A quick solution would be to download one of the numerous
freeware PC oscilloscope programs that can be found across
the web **broken link removed** looks
usefull as it features a spectrum analyser as well.

Automotive Stethoscope
http://circuitos.tripod.cl/schem/r40.gif

This is somewhat an ugly way of doing it though
and the trace(s) will take some time to get used to.

 

[stevez]

RK Nair - several have developed their own engine control systems, presumably with OBD capabilities - and they're sharing the results of their efforts via the internet. One of the guys was from Australia - engines were gasoline, not diesel but it's a place to start. I think I stumbled on to this while googling for OBD II information. Good luck.

 

[DirtyLude]

i dont know what the F1 pulse width is
BUT i imagin it has to do with spark..so you are going to need a spark sensor circuit..one of those things that clamps on the spark wire will do...

Actually it's FI, and he means Fuel Injector.

RK Nair - several have developed their own engine control systems, presumably with OBD capabilities - and they're sharing the results of their efforts via the internet.

Nobody in the aftermarket actually creates EFI systems with OBD in it. OBD is a regulated specification by the US EPA for emmissions regulations. It's actually quite difficult to create an ECU with all the controls to conform to the OBD II specification. The specification deals directly with detecting emmissions problems, misfires, cat converter failures, O2 sensor degradation. It doesn't care if you have no oil, and you seize your engine, as long as you're not poluting the air.

If you're talking about OBD scanners, yes, there's plenty of homemade ones out there, but that not going to help someone in India at the moment. Since their ECU's do not support OBD.

The problem with this project, is that you would need to actually hook into the existing engine sensors, which are not standard. 3volt return on a coolant temp sensor is different on a Volvo then a Honda. Same with MAP/MAF/MAS sensors. You would be able to get pulse width and rpm pretty easy by tapping into the fuel injector wire and the ignitor wire, but that's about it.

If all you want is the sensor return voltages, the pulse width, and rpm, you can use a simple multimeter with a hertz/pulsewidth feature and a calculator for all of it.

There must be some professional equipment out there with proper sensor calibration for different makes/models of engines/vehicles. I have no idea what they are, though.

 

[RK NAIR]

re

A quick solution would be to download one of the numerous
freeware PC oscilloscope programs that can be found across
the web **broken link removed** looks
usefull as it features a spectrum analyser as well.

Automotive Stethoscope
http://circuitos.tripod.cl/schem/r40.gif

This is somewhat an ugly way of doing it though
and the trace(s) will take some time to get used to.

Thanks a lot tansis .

 

[RK NAIR]

re

i dont know what the F1 pulse width is
BUT i imagin it has to do with spark..so you are going to need a spark sensor circuit..one of those things that clamps on the spark wire will do...

Actually it's FI, and he means Fuel Injector.

RK Nair - several have developed their own engine control systems, presumably with OBD capabilities - and they're sharing the results of their efforts via the internet.

Nobody in the aftermarket actually creates EFI systems with OBD in it. OBD is a regulated specification by the US EPA for emmissions regulations. It's actually quite difficult to create an ECU with all the controls to conform to the OBD II specification. The specification deals directly with detecting emmissions problems, misfires, cat converter failures, O2 sensor degradation. It doesn't care if you have no oil, and you seize your engine, as long as you're not poluting the air.

If you're talking about OBD scanners, yes, there's plenty of homemade ones out there, but that not going to help someone in India at the moment. Since their ECU's do not support OBD.

The problem with this project, is that you would need to actually hook into the existing engine sensors, which are not standard. 3volt return on a coolant temp sensor is different on a Volvo then a Honda. Same with MAP/MAF/MAS sensors. You would be able to get pulse width and rpm pretty easy by tapping into the fuel injector wire and the ignitor wire, but that's about it.

If all you want is the sensor return voltages, the pulse width, and rpm, you can use a simple multimeter with a hertz/pulsewidth feature and a calculator for all of it.

There must be some professional equipment out there with proper sensor calibration for different makes/models of engines/vehicles. I have no idea what they are, though.

Thank you LUDE for your clear info, but will it be possible to develop a engine monitor unit for diesel engine to monitor most of the parameters .
It is not necessory that it has to obey all the rules of OBD system.

 

[stevez]

Let me clarify an earlier post. Several individuals have created engine control systems (gasoline) using microprocessors/microcontrollers AND they have documented their efforts in a way that can be accessed via the internet. I think these engine control systems have an on-board diagnostic system - whether OBD I or II compliant or not is unknown to me - I don't think the developers were interested in the external interface. According to the website a group of interested individuals collectively purchased components, made boards, shared software, etc. At least one of the websites provided insight into the calculations for fuel control and how to interface with common automotive sensors. The information on this/these websites might be of significant help. If you find the website (Australia, I think) you may be able to contact people who can help you.