Does anyone know the voltage in the airbag system when it is static, non impact,I checked the voltage at the clock spring and found a voltage of 6 volts,the car in qustion had a small impact which set of the airbags. I purchased the drivers & passenger bags and fearfull of setting off the new ones I replaced the air bag sensor in the console the sensor in the front bumper. I hooked up the leonardo scanner but will not communicate with the airbag system. The Car is a 2000 360 F1. any insight will be helpful Thanks in advance.
By applying voltage with the clock spring disconnected, you have probably latched another fault in the airbag module. Did you test the voltage across the two pins or each one to chassis earth? I've seen the terminals referred to as the high side and low side. I'm not sure if the low side is earth. Try both methods. I couldn't find anything online about the airbag system integrity voltage. I've heard that a typical trigger voltage may be 30 volts, but I've seen a video of an airbag being triggered by a small 9 volt battery, so I would imagine the integrity voltage would have to be below this. To test airbag wiring, usually a 2.5 ohm resistor is hooked up in place of the airbag, but I think you'd need to reset the airbag computer beforehand to get rid of the latched faults. Experts?
I was hoping that the leonardo would comunicate with the air bag sensor still will not,guess keep probing the system.
you need to install simulators in the system and then pull up air bag resistances in the parameters. You should also perform a cycle test on the system and follow the instructions provided during the cycle test. Keep in mind that all air bag connectors have shorting bars on them so the air bag circuits are shorted together when the components or connectors are unplugged. This stops someone from accidentally setting off airbags. If your scanner doesn't have a cycle test or parameters option for the air bag module your using the wrong tools.
The shorting bars may only be on the airbag side of the connector. If you're getting voltage from the ECU with the connector disconnected, I'd say this would provide confirmation of this. Just wondering why the system uses 6 volts. Most automotive logic circuits use 12 or 5 volts.
Ian, I'm Getting the 6 volts with just the key on,I have'nt been able to find what the voltage if any would be present when the system is static.
Good point. I assume the system constantly monitors the airbags (when the car is running), not just with the ignition on. The WSM does say the light comes on for 4 seconds "on start up", but you'd want to know if the system developed a fault when the car is running, so you'd need a current flowing through the airbags at all times to monitor integrity. Unfortunately, there's not much you can do unless you find a compatible scanner. The WSM does mention using the Ferrari SD2 tool. I don't know if any others have had success with other scanners. The wiring diagrams show a wire going from the Airbag ECU to the OBD2 port, but I don't know if it's functional. Be sure to turn off the battery when reconnecting the connector. Wait 15 minutes before turning off the battery to allow stored voltages to discharge.
Thanks for your input,a thought came to me to check and see if the voltage remains the same when I start the car.
