Can any tech guys out there tell me if I purchase the ELM 327 tool, would I be able to read the codes from the ECU on my Bravo hgt. I know that it is a 3 pin connector and I have just aquired the adapter from Ebay so that the OBD will connnect, but will it then communicate and give accurate code readings ? If not, can you suggest another suitable reader please. Tony

the ELM interface is just that, an interface. you also need some software if you want to use the ELM interface. uniscan for example.

So do you reccomend that particular software or would another particular software such as scantool.net ? do you know of any software that has worked ok ?

I don't think the bravs use an OBD2 compliant protocol, so i think you'd be lucky to find some software that can communicate with it to be honest.

There must be something out there somewhere !! will keep looking on net. Have seen a Professional DB9/RS232 diagnostic Uniscan interface Tool including software that will run on DOS on Ebay for sale for £65 and they claim that it will work with all pre 2000 cars. Didn't really want to pay that much, although it would probably pay for itself in a couple of years.

i dont know about scantool.

the uniscan tool you've seen on ebay should work. uniscan is good for pre OBDII/EOBD cars and i've seen it working on a 1998 1.6 bravo.

jug said:

i dont know about scantool.

the uniscan tool you've seen on ebay should work. uniscan is good for pre OBDII/EOBD cars and i've seen it working on a 1998 1.6 bravo.

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good to know, cheers jug

not gonna work.. ELM327 is purely for proper OBD2 protocols, i.e. will mostly only work with USA cars after 2000, and european petrols after 2004. also pre 2004 european cars mostly implement only a subset of OBD2. Uniscan would work if you can get it, but again its pure DOS based (won't work in a DOS box in windows, needs a dedicated machine with 2 serial ports etc.) and so is of limited value..
Good tools do exist, but they cost good money..

stylers said:

ELM327 is purely for proper OBD2 protocols

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all the ELM interfaces can work with pre-OBD fiats.

they simply convert the RS232 signal used by the computer to an OBD signal used by the car. pre-OBD fiats use a modifed KWP2000 protocol so they are 99% OBD compatible already. that is why the ELM interface will work with them, but only if you use software that supports the fiat version of KWP2000 and 4 lengths of wire to connect the interface to the car's 3 pin diagnostic connector and the battery live.

not quite jug - these interfaces are actually protocol handlers, they don't just convert RS232 to OBD. they initiate and control the comms to the ECU, and send and receive their own formatted commands to/from the software, to remove the need for the software to handle the comms. think of it like a modem. the OBD2 FIAT protocols we are dealing with are "loosely" based on the standards, with subtle differences. thus these interfaces may or may not connect up, depending on the ECU's response, and then might work if the software was written to drive them, but nobody has done that yet.. so not an out of the box solution.

stylers said:

not quite jug - these interfaces are actually protocol handlers, they don't just convert RS232 to OBD. they initiate and control the comms to the ECU, and send and receive their own formatted commands to/from the software, to remove the need for the software to handle the comms. think of it like a modem.

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i have helped someone to build an elm323 interface. there is only 1 microprocessor and it is only a basic CMOS microprocessor with a very limited set of intructions . this is used as an interpreter, it is not capable of handling commands.

i assumed the elm327 was the same idea, however after checking it seems the 327 is a very different approach. it can automatically detect and translate protocols, even CAN. it has a command interpreter so it does more than simply translate, it can also initiate its own commands.

check out the differences on this diag: