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
Problem Symptoms Table
HINT:
- Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
- Inspect the fuses and relays related to this system before inspecting the suspected areas below.
WIRELESS DOOR LOCK CONTROL SYSTEM
| Symptom | Suspected Area | See |
|---|---|---|
| Wireless control function and entry function do not operate | Proceed to "All Door Entry Lock / Unlock Functions and Wireless Functions do not Operate" | Refer to All Door Entry Lock/Unlock Functions and Wireless Functions do not Operate |
| Wireless control function does not operate but entry function operates | Electrical key transmitter | - |
| Only answer-back function does not operate normally | Proceed to "No-answer back" | Refer to No Answer-Back |
| Only automatic lock function does not operate normally | Perform operation check | Refer to OPERATION CHECK |
| Lighting system (door courtesy light switch circuit) | Refer to Door Courtesy Switch Circuit | |
| Main body ECU (multiplex network body ECU) | - | |
| Only illuminated entry function does not operate | Perform operation check | Refer to OPERATION CHECK |
| Lighting system (door courtesy light switch circuit) | Refer to Door Courtesy Switch Circuit | |
| Main body ECU (multiplex network body ECU) | - | |
| Only door ajar warning function does not operate | Perform operation check | Refer to OPERATION CHECK |
| Lighting system (door courtesy light switch circuit) | Refer to Door Courtesy Switch Circuit | |
| Main body ECU (multiplex network body ECU) | - | |
| Panic alarm function does not operate | Perform operation check | Refer to OPERATION CHECK |
| Lighting system (int) (interior lights) | Refer to PROBLEM SYMPTOMS TABLE | |
| Lighting system (ext) (headlights, taillights, hazard warning lights) | Refer to PROBLEM SYMPTOMS TABLE | |
| Theft deterrent system (vehicle horns, security horn) | - | |
| Main body ECU (multiplex network body ECU) | - | |
| Remote air conditioning system does not operate | Proceed to "Air Conditioning System" | Refer to PROBLEM SYMPTOMS TABLE |
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.