DTC B2790: Id Code Box Circuit

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.

DTC detecting condition:

When EEPROM cannot be written in or readout response is absent.

Trouble symptom:

Engine will not start.

CAUTION:

For replacement procedure of ID code box, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION

CHECK DTC .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, perform the clear memory of [Keyless Access with Push Button Start (Collation)]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY
3. Register the ID code box. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
4. Read the DTC of [Keyless Access with Push Button Start (Collation)] using the Subaru Select Monitor. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)
Is DTC B2790 displayed? (Current malfunction)

Yes : Replace the ID code box. Ref. to SECURITY AND LOCKS>ID CODE BOX

No : ID code box registration was not performed properly.