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
Repair Instruction: Initialization: Initialization
WARNING: This page is about a different variant/trim than selected.
- PROCEDURES NECESSARY WHEN AUXILIARY BATTERY TERMINAL IS DISCONNECTED/RECONNECTED
Necessary Procedures Effect/Inoperative Function When Necessary Procedures are not Performed See Unlock back door Back door opener Refer to INITIALIZATION NOTE:After the power switch is turned off, the navigation receiver assembly (for Navigation Receiver Type) or radio and display receiver assembly (for Radio and Display Type) records various types of memory and settings. As a result, after turning the power switch off, make sure to wait at least 60 seconds before disconnecting the cable from the negative (-) auxiliary battery terminal.
- PROCEDURES NECESSARY WHEN ECU OR OTHER PARTS ARE REPLACED
Replacement Part Necessary Procedure Effect/Inoperative Function when Necessary Procedures are not Performed See ECM Vehicle Identification Number (VIN) registration MIL comes on Refer to REGISTRATION Power management control ECU Code registration (Engine immobiliser system) Hybrid control system start Refer to REGISTRATION Current sensor offset learning Hybrid system warning light illumination Refer to INSTALLATION - Step 34 Hybrid battery junction block assembly Current sensor offset learning Hybrid system warning light illumination Refer to INSTALLATION - Step 34 HV battery Recovery inspection - Refer to RECOVERY INSPECTION - Battery diagnosis
- Battery status info update
HV battery status information cannot be updated and the previous status continues to be shown Refer to UTILITY Hybrid vehicle supply stack sub-assembly Recovery inspection - Refer to RECOVERY INSPECTION Battery diagnosis Cannot identify the stack to be replaced Refer to UTILITY Normal battery stack average voltage calculation Cannot specify the product number of the stack to be replaced Battery status info update HV battery status information cannot be updated and the previous status continues to be shown Millimeter wave radar sensor assembly Adjust millimeter wave radar sensor assembly - Dynamic radar cruise control system
- Pre-collision system
Refer to ADJUSTMENT - Tire pressure warning ECU
- Tire pressure warning valve and transmitter
- Transmitter ID registration
- Initialization
- When DTC detection conditions of "transmitter ID not received" DTC are met, TPWS indicator blinks for 1 minute, and then illuminates.
- Tire pressure warning function
Refer to REGISTRATION for Registration
Refer to INITIALIZATION for InitializationBrake booster with master cylinder - Initialization and calibration of the linear solenoid valve
- Yaw rate and acceleration sensor zero point calibration
- ABS warning light illumination
- Brake warning light/yellow (minor malfunction) illumination
- Slip indicator light illumination
- VSC disable or malfunctioning
Refer to INITIALIZATION for Initialization
Refer to CALIBRATION for Calibration- Brake pedal stroke sensor
- Brake pedal
- Clearing stored linear solenoid valve calibration data
- Initialization and calibration of the linear solenoid valve
Refer to INITIALIZATION Yaw rate and acceleration sensor - Clearing zero point calibration data
- Yaw rate and acceleration sensor zero point calibration
Refer to CALIBRATION Power steering ECU assembly - Torque sensor zero point calibration
- Assist map writing
- P/S warning light comes on
- EPS control
Refer to CALIBRATION Steering column assembly Torque sensor zero point calibration Steering effort is different between turning steering wheel to left and right - Map light assembly
- Garage door opener transmitter
Re-registration of codes in the garage door opener system - Register transmitter code
- Rolling code systems
Garage door opener system Refer to REGISTRATION DCM (Telematics Transceiver) DCM activation Safety connect system Refer to DCM ACTIVATION - Certification ECU (smart key ECU assembly)
- Transmission control ECU assembly
- ID code box (immobiliser code ECU)*1
- Electrical key transmitter sub-assembly
Code registration (Engine immobiliser system) - Wireless door lock control system
- Smart Key system*2
- Push-button start*3
- Hybrid control system start
- Steering lock system
Refer to REGISTRATION - Occupant detection ECU
- Front passenger seat
- Zero point calibration
- Sensitivity check
- Occupant classification system
- Passenger airbag ON/OFF indicator
- Airbag system (Front passenger side)
- Seat belt warning system (Front passenger)
Refer to INITIALIZATION - Door window regulator assembly
- Power window regulator motor assembly
- Door glass
- Door glass run
Initialize power window control system - Auto up/down function
- Jam protection function
- Operation function after power switch is turned off
Refer to INITIALIZATION - Headlight leveling ECU assembly
- Rear height control sensor sub-assembly
Perform Headlight leveling ECU initialization Automatic headlight beam level control function Refer to INITIALIZATION - *1: for Canada
- *2: w/ Smart Key System (for Entry Function)
- *3: w/o Smart Key System (for Entry Function)
Factory Service Tools
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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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