Depending on what airbag ECU is fitted in your car FiatECUScan might or might not be able to help you.
FES does not support the TRW2 type ECU. Check your ECU, it's located under the back seat. If the p/n is 60625181 you have a TRW2 type, and there's currently no avaliable DIY software avaliable to read error codes or clear errors (= reset the light).
If you have the Becker ECU (60610206) you can read and reset faults without any other tools than a paper clip. I wrote a detailed description in this thread:
I think FES supports the airbag ECUs in cars from -98 and onwards, but the part number of the ECU is the definite key here.
My apologies if this post is too long. If so, please delete at your convenience. Just trying to help.
Resetting the Airbag Light on Phase 1, 916 GTVs and Spiders With TRW2 and Becker Airbag ECUs
Firstly, MultiECUSCAN , FiatECUScan, AlfaDiag, AlfaOBD etc do not connect to, or diagnose or reset the TRW ECU part number, 60625181 or the Becker ECU part number, 60610206.
The Becker ECU can be re set without diagnostic gear, simply earth the K – line for between 5 and 10 seconds, and the warning light will be reset, provided you have corrected the error that caused it in the first place.
You can use MultiECUScan etc. on all Phase 2 and 3 cars, so don’t throw it out just yet.
TRW 2 ECU What Do I Need?
1. A KKL 16pin to USB adapter available off ebay.
2. A 16 pin to three pin Fiat adapter also available off ebay.
3. A home made two wire pin to socket harness.
4. Laptop running Microsoft.NET framework. Available here:
5. Software from Peter Feil. Available here for free :- ( This also contain MAC software )
To make it easy, create a folder on C:\ that you name with a name that you will remember (as an example, trw2scan), copy all trw2scan files to that folder (have you extracted the trw2scan.zip file ?).
At the command prompt (you are at C:\Windows\System32>) type cd/ (and press Enter),
now you are at C:\>, type cd trw2scan (or the name of the folder you created) and press Enter,
now you are at C:trw2scan> you can type dir and press Enter to see the files in the folder and to run the program you type trw3.obd and press Enter once you are connected to the ECU and the ignition is switched to MAR.
6. Drivers for your KKL adapter . Available here:-
http: //www.ftdichip. com/Drivers/CDM/CDM20814_Setup. Exe
TRW2 ECU Where Do I Connect?
On the GTV you have to remove the rear seat squab and the three pin socket will be there.
On the Spider, remove the lining from the battery compartment behind the seats. In the centre is a gold anodized sheet metal shield covering the Airbag ECU. Remove the two nylon speed nuts ( be careful not to dislodge the studs that are a weak press fit into the sheet metal. These tend to get lost in one of the many holes in the floor of the battery compartment. Don’t ask me how I know this !)
Below this cover, you will see the ECU. Firstly determine whether it is a Becker or TRW unit.
Attached to the ECU will be a yellow cable that has a pigtail coming off it ending in a three pin socket. This should have a dust cover over the terminals. Pull this off and keep it safe.
TRW2ECU How Do I Connect?
Use the two wire harness that you made up to bridge between the K – Line and Earth on the diagnostic port (attached to the ECU) and the Fiat three pin adapter.
You could be more drastic / simplistic and simply cut the L – Line on the diagnostic port. If you peel back the yellow sheathing carefully, the wire to cut is the Light Blue / White. The Black wire is the Earth and the White / Red wire is the K – Line.
L E K
Refer to the above diagram of the diagnostic port. The line between the end and the tab in the plastic insulating body, is the L – Line that must not be connected.
Don’t forget to connect the red wire of the three pin Fiat adapter to a power supply. Battery is pretty close!
Now the fun begins.
Ensure that the ignition is switched to the MAR position. Indicator lights on the instrument panel but engine not running.
Refer to point 5 above and run the program. When it prompts you to re set the error codes, press ”y” and Enter.
Disconnect your cables and turn the ignition off. Now, when you turn on to the MAR position, the airbag light should switch on for four seconds before going out.
Becker ECU Procedure
The Becker unit can also display error codes by blinking the warning light. You activate the blinking by connecting the K – Line (pin 3) to ground for 1 to 5 seconds. If more than one error is present they are shown sequentially. Errors are decoded according to the following:
01 blinks - no fault
02 blinks - sensor fault
03 blinks - airbag ignition circuit short circuit to VBatt
04 blinks - airbag ignition circuit short circuit to GND
05 blinks - driver airbag charge resistanstance out of tolerance
06 blinks - passenger airbag charge resistanstance out of tolerance
07 blinks - battery low voltage
08 blinks - faulty warning lamp or wiring
09 blinks - crash data present
10 blinks - pretensioner ignition circuit short circuit to VBatt
11 blinks - pretensioner ignition circuit short circuit to GND
12 blinks - primary circuit of the driver pretensioner interrupted
13 blinks - primary circuit of the passenger pretensioner interrupted
Note that "driver" and "passenger" probably refers to a car for the Italian market, i.e. left hand drive. It might be the other way around for a RHD car. Fault codes can be deleted (exception fault code 09) by connecting pin 3 to ground for 5 to 10 seconds. One fault at the time is deleted.
If you get a fault code 09, you will require a replacement ECU or have an expert repair your unit. It involves removal of the EPROM and a bit of re – coding. There are services on the internet that offer this service.
If you experience error 05, 06, 12 or 13 try cleaning the corresponding connector in the yellow cable harness.
If you get an 07 error, you will have to either re – charge your battery if it is a healthy unit, or buy a new one if yours is past it.
Other Items To Check
Disconnect the airbag ECU from the car. Does the warning light go off? The warning light is supplied by the ignition and grounded by the ECU. If it remains on when disconnected from the ECU, there's a short in the warning light wiring somewhere.
The following refers to the pins on the ECU that will only be seen when the large plug attached to the yellow cable is unplugged. WARNING Only disconnect this once the battery has been disconnected for at least 15 minutes.
Check the ECU ground.
Check continuity from pin 14 to the car body. Check resistance if you can.
Probably best with the ECU disconnected from the car :
Check continuity and resistance between each device pin on the ECU and related pretensioner/airbag.
Check continuity between : ( wiring and wire colour from Pre May 1997 Phase 1 )
ECU pin 6 and RH pretensioner pin 1 ( Brown wire )
ECU pin 7 and RH pretensioner pin 2 ( Brown-Black wire )
ECU pin 11 and LH pretensioner pin 1 (Green-Black wire )
ECU pin 10 and LH pretensioner pin 2 ( Green wire )
ECU pin 3 and passenger airbag pin 1 ( Yellow-Black )
ECU pin 4 and passenger airbag pin 2 ( Yellow wire )
ECU pin 1 and driver airbag pin 1 ( Blue-Black )
ECU pin 2 and driver airbag pin 2 ( Blue wire )
I'd be very careful about doing this because I wouldn't want to put any voltage across the explosive device so if you do it'd be worth downloading the workshop manual for this to ensure you're getting the pins correct and also as a sanity check look at the colour of the wire each end. Or maybe disconnect the airbags/pretensioners first.
Difficult to advise further really as I wouldn't want to take any chances with explosive devices! The manual states you should be disconnecting the airbags and pretensioners and putting loads across them (value unknown) before doing any diagnostics (OK I imagine if just resetting).
I also looked through the troubleshooting guide in the workshop manual (volume 3 Section 55-23) and there's not a lot else it can suggest.