Battery Run Flat Following Passenger Airbag Fault Message

[standishgeezer]

Hi, I'm new to this forum so hoping you may be gentle with me :-)    Citroen C5 HDI VTR (2004) . About a week ago a 'Passenger Airbag Deactivated' message came up (accompanied by the normal beeps and warning lights). After restart the message disappeared and all seemed well. Today however, the vehicle would not start and the battery completely drained quickly. Now, the battery was replaced about a month ago and has been great until now.  I'm wondering whether it is possible that the airbag fault is connected - perhaps by causing a parasitic drain? Views would be appreciated.

[Guest Parkesie]

Battery or alternator could be dead, double check your terminals are clean and secure as well.

[paul.h]

Could also be a problem with the passenger airbag switch or its connector/wiring.

If you have a towbar, remove its fuses but unlikely to be this - ours drains the battery over about 4 weeks if the car is not used. If you need to check for a parasitic drain, use a meter to measure current across each fuse once the bsi has shut down. When I was checking about 15 milli amps is about normal total and found the towbar was also taking about 20 milli amps.

[standishgeezer]

Thanks for your thoughts so far people. i went to car this afternoon to check airbag cables etc. but, before doing anything thought I would try giving the engine a quick crank in the hope that it may just 'catch'. To my surprise, the engine crank was quite lively (after the battery draining yesterday  and it being quite cold at about 4 degrees today) with the car starting quickly! :o   Went for a short run up and down the motorway and, on return, shut down & measured battery voltage which was 12.6V. I then fired up again and tested voltage at idle which read 14.3V.  These seem quite good readings to me and seem to show 1) the battery is good (as expected - since the battery is quite new) and has recovered from being run flat. 2) the charging system is working ok.

 

I'm still therefore puzzled what caused the drained battery scenario yesterday  :unsure: