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 4Runner TrailFACTORY OEM SERVICE PROCEDURE
Diagnostic Trouble Code Chart
HINT:
If a trouble code is output during the DTC check, inspect the trouble areas listed for that code. For details of the code, refer to the "See" below.
CERTIFICATION ECU
| DTC Code | Detection Item | Trouble Area | See |
|---|---|---|---|
| B27A1 | Open in Driver Side Electrical Antenna Circuit | - Harness or connector - Front door outside handle assembly (for driver side) - Certification ECU |
Refer to DTC B27A1: Open in Driver Side Electrical Antenna Circuit |
| B27A2 | Open in Front Passenger Side Electrical Antenna Circuit | - Harness or connector - Front door outside handle assembly (for front passenger side) - Certification ECU |
Refer to DTC B27A2: Open in Front Passenger Side Electrical Antenna Circuit |
| B27A5 | Open in Front Floor Electrical Key Oscillator Circuit | - Harness or connector - Indoor No. 1 electrical key antenna (front floor) - Certification ECU |
Refer to DTC B27A5: Open in Front Floor Electrical Key Oscillator Circuit |
| B27A6 | Open in Rear Floor Electrical Key Oscillator Circuit | - Harness or connector - Indoor No. 2 electrical key antenna (rear floor) - Certification ECU |
Refer to DTC B27A6: Open in Rear Floor Electrical Key Oscillator Circuit |
| B27A7 | Open in Inside Luggage Compartment Electrical Key Oscillator Circuit | - Harness or connector - Indoor No. 2 electrical key antenna (inside luggage) - Certification ECU |
Refer to DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit |
| B27A8 | Open in Outside Luggage Compartment Electrical Key Antenna Circuit | - Harness or connector - Electrical key antenna (outside luggage) - Certification ECU |
Refer to DTC B27A8: Open in Outside Luggage Compartment Electrical Key Antenna Circuit |
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.