DTC B1571 Reference Code Incompatibility (Immobilizer Control Module To ECM): Trouble Symptom

WARNING: This page is about a different car, the 2016 Subaru Impreza and 2016 Subaru Crosstrek. However, it is still accessible from the selected car via links, so may be relevant.

Engine will not start.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK ECM. Perform ECM registration. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.	Is ECM registration finished? And does the engine start?	ECM registration was not performed properly.	Go to step 2.
2 REPLACE ECM. Install the ECM from other normal operating vehicle (with push button start) which use same ECM to the vehicle to be diagnosed. Perform ECM registration. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.	Is ECM registration finished? And does the engine start?	Replace the ECM. < Ref. to REMOVAL , Engine Control Module (ECM). > < Ref. to REMOVAL , Engine Control Module (ECM). > Install the ECM from other vehicle to the original vehicle.	Replace Keyless access CONTROL MODULE (model without ID code box), < Ref. to KEYLESS ACCESS CONTROL MODULE . > or replace ID code box (model with ID code box). < Ref. to ID CODE BOX . >