I could tell you loads of reasons why the air bag light could be illuminated, but you still need to take it to your dealer to sort it. Common faults are PAB loom incorrectly routed by glove box lid, catches and records an error. PAB exclusion switch, bad earth! most common. But without a diagnostic computer you can't do a thing. Stilo's self learn and can extinguish the failure lamp but punto's have to be done electronically.