DTC B1571 Reference Code Incompatibility (Immobilizer Control Module To ECM): DTC Detecting Condition
WARNING: This page is about a different car, the 2016 Subaru Outback and 2016 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
Incompatibility of reference code between keyless access control module (model without ID code box) or ID code box (model with ID code box) and ECM occurs.