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Newbie on Grande Punto has some questions

Posted: 23 Apr 2011, 12:59
by 18tbx46
Hi everyone,..

I have a 2006 GP 1,3MJet. Since 1,5 years, I have troubles with the MIL indicator. The first time, it goes on, I went to the workshop for reading the failure code.
They said mass airflow sensor and replaced it. A few week s later the MIL comes again, but the workshop could not manage the failure till today. They just clear it every time (but they take no money, so its ok)
Now I decided to read and clear the codes by myself, so I bought a ELM interface on ebay. Yesterday I got it, but I have some troubles with it:

First, I opened the enclosure to check out whats inside (due to my work, I'm firm in elctronics). It is a ELM327 clone on some kind of PIC µc, the usb connection runs over ft232rl, the can frontend is a mcp2551 with a termination resistor of 120 ohms.
That looks ok for me. I modified the interface with a small dpdt switch, to change the CAN pins from 6/14 to 1/9. After installing the FTDI driver and FES freeware on my laptop, it was time for a first try. After changing the baudrate to the correct 38400 I could connect to the ECU and the Power Steering via high speed CAN at PIN 6/14. Because of the free FES I could not read anything, but the connection works. Now I changeed to PIN 1/9 (low speed CAN). On this PINs I should have access to Body Computer, Airbag, and Service Reset. There is also the "Can Info" which should work with free FES. But the only message I got was: "Conncetion Failed". So I checked my modification of the interface again, but there was definitly no error in the physical connction to the obd connector. I had no idea.
But with the interface comes some kind of demo version of another obd software (scanmaster), so I tried to get a connection with this software,.. first try was negative, but the software has a selection box for the obd protocoll. I changed it from "automatic" to "can 11bit id / 250kbit/s" (this was the lowest speed in the box) although I know that low speed Can is 50k/bit...
Now the software could connect, so the physical connction to low speed can must work.
Then I click the "read error codes button",.. this was a big mistake,... because the next thing was a beeep from the dashboard,... the car says "Airbag Failure" !!! Oh Sh..

Again , I tried to connect with FES but it doesnt work,.. so now I had an airbag failure but no idea...

But there was another thing,.. I changed to high speed CAN an click the "scan button" in FES. The scanning procedure runs and identifies the Marelli 6F3 diesel injection, the Delhpi Power Steerinng and the ABS Unit,.. but the ABS Unit was not identified correct,.. (wrong ISO code, or some what), and also the dashboard beeps again --> ABS / EBD failure !!!
Now I had enough,.. I disconnected the interface, before I destroy the complete car.

After reading this forum I found out that the Airbag Failure should go away, after 20 successful start ups. And yes,.. I think I had enougt luck,.. it goes away,.. I hope it dont come back. Also the ABS / EBD Failure goes away,.. I tested the ABS on a loose underground, an it works correct.



Now I have some questions:

What could be the problem with the low speed can ?
I dont can connect to any device on it with FES, but the other software could.

Is it possilbe, to destroy the airbag control unit by causing some troubles on the low speed CAN ?

And,.. the low speed CAN is decribed to has 50kBit/s speed. But the in the datasheet of the ELM327
the only speed ratings mentioned, are 250kBit and 500kBit. Will this work ?

and one Note to my interfce: FES say in the selftest: "ELM327 1.4 compatible, should work with all CAN devices"


best regards, Manuel