Hello, all. I'm working on figuring out some Passlock 1 issues with a 1997 Buick Skylark. It keeps having to be relearned. It will normally work fine for days or weeks, but then one day enter short tamper when I try to start it. Several failed attempts and it goes into long tamper and relearns. It will then work fine again for hours, days, weeks... or sometimes go right back into short tamper again.

The shop found several codes on it, including a B1028. The recent DTC code lists I've seen have that as something completely non-security related, but I have also seen mention of it on older N-body cars being a code for "crank low security signal fault."

If that'* the case, would it mean that the crank low signal is not being sent at all? Or does it mean that the crank low signal is not what is expected?

I'm trying to figure out if it looks more like a cylinder housing/Passlock sensor fault, an IPC fault, or a wiring fault.

Other codes set were a B1026 and a P1629.

Thanks!