My BMW 316i SE 2001 had an intermittent starting problem. Sometimes it would start ok, other times it would try to turn over but not start, then show up SRS orange light error and turn the hand brake warning light orange.
A new forward intake Cam Sensor was required.
A garage wanted to charge me £150/$240USD
I researched and found it was a 3 minute job, so did it myself.
Hopefully this CAM sensor Replace DIY will help you too!
B220.127.116.118.628 CAM sensor