Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Toyota Avalon TRDFACTORY OEM SERVICE PROCEDURE
LIN COMMUNICATION SYSTEM (for Gasoline Model)
LIN COMMUNICATION SYSTEM (FOR GASOLINE MODEL) DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION
| DTC Code | Description |
|---|---|
| B1206 | P/W Master Switch Communication Stop |
| B1273 | Sliding Roof ECU Communication Stop |
| B2321 | D-Door Motor ECU Communication Stop |
| B2322 | P-Door Motor ECU Communication Stop |
| B2323 | RR-Door Motor ECU Communication Stop |
| B2324 | RL-Door Motor ECU Communication Stop |
| B2325 | LIN Communication Bus Malfunction |
| B2785 | Communication Malfunction between ECUs Connected by LIN |
| B2786 | No Response from Steering Lock ECU |
| B278C | Lost Communication with Power Source Control |
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.