DTC B278A: Short to GND in Immobiliser System Power Source Circuit [10/2018 - ]: Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
When there is a short to GND in the power supply for the transponder key amplifier of the power switch, the certification ECU (smart key ECU assembly) stores this DTC.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Note |
|---|---|---|---|---|
| B278A | Short to GND in Immobiliser System Power Source Circuit | A short to GND in the power supply of the transponder key amplifier of the power switch (VC5 - VC5) detected. (1 trip detection logic*) |
|
DTC output confirmation operation:
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- *: Only output while a malfunction is present.
VEHICLE CONDITION AND FAIL-SAFE OPERATION WHEN MALFUNCTION DETECTED
| Vehicle Condition when Malfunction Detected | Fail-safe Operation when Malfunction Detected |
|---|---|
| Hybrid control system cannot be started when transmitter battery is depleted by holding transmitter near power switch and pressing and holding power switch with shift lever in P | - |
RELATED DATA LIST AND ACTIVE TEST
| DTC No. | Data List and Active Test |
|---|---|
| B278A | - |