DTC P177A-87: Lost Communication with Gear Shift Control Module Backup Power Supply Missing Message [08/2023 - ]: 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.
The shift control ECU sends backup request signals to the integrated capacitor according to BUBO signals.
The shift control ECU receives backup mode and malfunction notification signals from the integrated capacitor according to BUBI signals.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Warning Indicate | DTC Output from | Priority | Note |
|---|---|---|---|---|---|---|---|---|
| P177A-87 | Lost Communication with Gear Shift Control Module Backup Power Supply Missing Message | When the ignition switch is ON and the battery voltage is a certain value or more, communication malfunction with the integrated capacitor is detected (1 trip detection logic) |
|
Does not come on | Multi-information Display Error Message
|
Transmission | A | SAE: P177A |