The under seat connections are for the airbag occupant detection. They simply tell the system if someone is in the seat, and if they are over a set weight it also sets the level that the air bag deploys at. So say a fifty pound child sets there the SRS will deploy the bag at a lower level than if a 200 pound adult is in the seat.
Because this started after a low battery was replaced and this is a Peugeot my first suspicion would be the airbag control module itself. They have a supplemental power source inside them in the event the main battery gets cut off during an accident. It's designed to only supply power for a short time. When the main battery gets low it can drain that internal unit, then when full power is restored with the new battery it doesn't re-charge the internal supply but instead damages the module.
For the problem you have with that code you need to find a shop that can fully scan the systems in it. That will likely require a dealer scan system as many euro vehicles use different connections for diagnostics on the restraint systems. The catch is that it will need to be scanned while the light is on, this is because the SRS system is a constant monitor system. It watches all the parts all the time. If it's something like a broken wire or a bad connection and it "fixes" itself and the light goes out, it may not show a code as the system thinks it is working fine. It will not show an active code and instead may show it as a memory code. That can be hard to find without the high end scan tool.
Thursday, February 21st, 2019 AT 5:07 AM