B1602 — PATS Received Invalid Format Of Key-Code From Ignition Key Transponder
What it means
B1602 is an OBD-II diagnostic trouble code: PATS Received Invalid Format Of Key-Code From Ignition Key Transponder.
Typical fix
Confirm the code with an OBD-II scanner, then inspect the component or circuit named above. Consult a vehicle-specific service manual for the full diagnostic and repair procedure.