DTC B1577: IMM Control Module EEPROM

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

Diagnosis start condition:

Battery voltage is 10 V or more.
The remote engine starter was not used to start the engine.

DTC detecting condition:

Defective body integrated unit or immobilizer control module
Failed to access ROM in the body integrated unit or the immobilizer control module

Trouble symptom:

Engine will not start.
The security indicator illuminates.

CAUTION:

When the body integrated unit or immobilizer control module is replaced, registration of the immobilizer system is required. For details, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

PERFORM ECM REGISTRATION .
Perform ECM registration. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

Is registration complete?

Yes : Finish the diagnosis.

No : Go to 2.
PERFORM ECM REGISTRATION .
1. Using the Subaru Select Monitor, perform the clear memory of [Engine]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY
2. Perform ECM registration. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
Is registration complete?

Yes : Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE:
In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

No : Refer to "Correspondence table when registration is not possible" in the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume. If the registration still does not work properly, replace the following parts.
- Body integrated unit (except for C0 model) Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT
- Immobilizer control module (C0 model) Ref. to SECURITY AND LOCKS>IMMOBILIZER CONTROL MODULE