DTC B278E-87: Immobilizer Amp Missing Message [10/2022 - ]: Procedure

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

CLEAR DTC

Clear the DTCs.

Body Electrical > Smart Access > Clear DTCs

Result

Proceed to
NEXT

Result:

NEXT

See step 2

CHECK FOR DTC

Press the engine switch with the electric key transmitter sub-assembly not in the cabin.

Check for DTCs.

Body Electrical > Smart Access > Trouble Codes

Result

Result	Proceed to
B278E-87 is output	A
B278E-87 is not output	B

Result:

A

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [10/2022 - 08/2023] , or refer to REMOVAL [08/2023 - ]

Result:

B

USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ]