DTC B278E-87: Immobilizer Amp Missing Message [10/2022 - ]: Description
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.
A transponder key amplifier is built into the certification ECU (smart key ECU assembly).
When a communication malfunction occurs with the transponder key amplifier inside the certification ECU (smart key ECU assembly), this DTC is stored.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | DTC Output from | Priority | Note |
|---|---|---|---|---|---|---|
| B278E-87 | Immobilizer Amp Missing Message | A communication malfunction with the transponder key amplifier inside the certification ECU (smart key ECU assembly) is detected. (1-trip detection logic*). | Certification ECU (smart key ECU assembly) | Smart Access | A | DTC Output Confirmation Operation:
|
- *: Only detected while a malfunction is present and the ignition switch is ON.
VEHICLE CONDITION AND FAIL-SAFE FUNCTION WHEN MALFUNCTION DETECTED
| Vehicle Condition when Malfunction Detected | Fail-safe Function when Malfunction Detected |
|---|---|
| Engine cannot be started when transmitter battery is depleted by holding electrical key transmitter sub-assembly near engine switch and pressing and holding engine switch with shift position in P | - |
RELATED DATA LIST AND ACTIVE TEST ITEMS
| DTC No. | Data List and Active Test |
|---|---|
| B278E-87 | - |