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
Engine Immobiliser System
CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) DTC IDENTIFICATION
| DTC Code | Description |
|---|---|
| B2784 | Antenna Coil Open / Short |
| B278A | Short to GND in Immobiliser System Power Source Circuit |
| B2790 |
ID BOX EEPROM Malfunction |
POWER MANAGEMENT CONTROL ECU (HV CPU) DTC IDENTIFICATION
| DTC Code | Description |
|---|---|
| B2799 | Engine Immobiliser 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
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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.