DTC B278E-87: Immobilizer Amp Missing Message [09/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus TX 550h+ and 2024 Lexus TX 500h. 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 power 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 [09/2023 - 12/2023] , or refer to REMOVAL [12/2023 - ]

Result:

B

USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - ]