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.
2012 Toyota Prius TwoFACTORY OEM SERVICE PROCEDURE
Smart Key System (Keyless Start) (Except Plug-In) (Diagnostic Codes & Symptom Tests)
- SMART KEY SYSTEM (for Start Function)
- On-Vehicle Inspection
- DTC B2271: Ignition Hold Monitor Malfunction
- DTC B2274: ACC Monitor Malfunction
- DTC B2275: STSW Monitor Malfunction
- DTC B2277: Detecting Vehicle Submersion
- DTC B2282: Vehicle Speed Signal Malfunction
- DTC B2284: Brake Signal Malfunction
- DTC B2286: Runnable Signal Malfunction
- DTC U0293: Lost Communication with HV ECU
- Symptom Tests
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.
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