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.
2011 Toyota Avalon BaseFACTORY OEM SERVICE PROCEDURE
Smart Key System
CERTIFICATION ECU DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION (TO 12/2010)
| DTC Code | Description |
|---|---|
| B1242 | Wireless Door Lock Tuner Circuit Malfunction |
| B2784 | Antenna Coil Open / Short |
| B2785 | Communication Malfunction between ECUs Connected by LIN |
| B2786 | No Response from Steering Lock ECU |
| B2789 | No Response from ID BOX |
| B278A | Short to GND in Immobilizer System Power Source Circuit |
| B2790 | ID BOX EEPROM Malfunction |
ECU DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION (TO 12/2010)
| DTC Code | Description |
|---|---|
| B2799 | Engine Immobilizer System Malfunction |
| B279A | Theft Deterrent System Communication Line High Fixation |
| B279C | Theft Deterrent System Presence Detection |
CERTIFICATION ECU DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION (FROM 12/2010)
| DTC Code | Description |
|---|---|
| B1242 | Wireless Door Lock Tuner Circuit Malfunction |
| B2784 | Antenna Coil Open / Short |
| B2785 | Communication Malfunction between ECUs Connected by LIN |
| B2786 | No Response from Steering Lock ECU |
| B2789 | No Response from ID BOX |
| B278A | Short to GND in Immobilizer System Power Source Circuit |
| B2790 | ID BOX EEPROM Malfunction |
ECU DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION (FROM 12/2010)
| DTC Code | Description |
|---|---|
| B2799 | Engine Immobilizer System Malfunction |
| B279A | Theft Deterrent System Communication Line High Fixation |
| B279C | Theft Deterrent System Presence Detection |
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.