Bump. I have this same problem with my 2008 Sierra 1500. The light is on, no DIC message, Onstar email correctly reports proper inflation in all 4 tires, I verified my spare is properly inflated, and also Onstar said they could pull no error code for it (asked because I coincidentally now also have a B0083 air bag code... no idea).
I've done the relearn process and also tried disconnecting the battery for 10 mins. Maybe it is saying the sensor battery is low but still operating? Not that I know where or how to replace it.
