So, the faulty pass lock sensor is a SEPARATE issue from the lock cylinder that would need replacing assuming the voltage results from the BCM diagnostic wire tests are negative? If so, based on the information, should the cylinder replacement occur first?
After looking for stored codes, that so far has yielded no results, your first suggestion about cause was the pass lock sensor, then proceeded to prescibe a replacement of lock cylinder and its housing.
Are you saying that, even after replacing the cylinder, the issue may continue until the pass lock senser is replaced? If you suspect the sensor, then why not replace it first?
One shop did suggest the cylinder, btw, but without the diagnosis procedure you provided and without any assurance of a fix.
Got it about the relearn (reset) procedure, something that was recommended and tried once, at least partially.
The issue, remember, is a theft light, no start until it quits blinking (about 7-8 minutes) and normally starts with 2nd try, an issue that's gone on for years without getting much worse with this Olds, same as the Malibu.
Thank you for your patience and knowledge.