B0100-49

When starting my van on an icy Spring morning back in 2021, I had the dreaded B0100-49 fault, airbag warning light came on. My van is a 2018 Ducato based Rapido, so I was surprised when the fault appeared on such a recent van . I went to the dealer who services the van, he told me this was a common fault, but as the van who only just 3 years old, Fiat might supply a new part as a goodwill gesture. He told me he would deal with it at my next service in a few months, he would need to put the van on their diagnostics ( cost additional £100, my thought was if the van was being serviced, then surely they would run diagnostics as part of the service ), but if Fiat wouldn't supply the part free, then it would cost approx £1500 to fix. . I drive the van every few weeks, and a couple of weeks later, I was surprised to find the light had gone out, and the fault cleared itself. At the service, the dealer said he couldn't find any trace of the fault.

About the beginning of April this year, I was taking the van out for a drive. While going around a roundabout, the fault appeared again. This time the light didn't go out. I had the battery replaced just in case that would help, it didn't, the mechanic told me there was nothing wrong with my battery. Taking advice on the forum , I contacted Crash data, they told me they were very busy and couldn't guarantee a fast turnaround, I was going to France and my ferry was only a week away, so I decided to just put up with the warning light until I came home. I sent the ecu to Crash data on Monday afternoon, got an email on Tuesday lunchtime saying the unit was fixed and had been dispatched, I received it back on Wednesday and it was back in the van less than 48 hours after it had been removed.

They supplied a print out of the fault details, this showed that I was travelling at 32mph and the fault was caused by a battery voltage of 14.5 v. Has this happened to anyone else on the forum? As the original battery was ok, what would cause the battery voltage to be so high, I am concerned this fault will happen again. Or was it an unexplainable event that just happens?

Its a common fault on all the sevel based vehicles (ducato/boxer/relay) the airbag module is prone to voltage spikes and it usually happens after the van has been stood for a period of time. My boxer did it twice and crash data resolved it both times. I was told that the battery should be fully charged if it has been sitting for a while to help prevent it, or keep using the vehicle.

The strange thing is if its the module going faulty the warning light will not go off, the fact yours did would suggest a possible connection issue which would more than likely come from the seats especially if they are captains chairs and rotate. The constant movement back and forth and turning can cause a break in a cable or pull one wire back from making a true contact in a plug.

You might need to get an autospark just to check it out

PM sent.