Toyota Yaris: Theft Deterrent System / Problem Symptoms Table

The theft deterrent system cannot be set or canceled

Proceed to "Security Indicator Light Does not Blink"

IG signal circuit

Door unlock detection switch circuit

Front door courtesy switch circuit

Back door courtesy switch circuit

Engine hood courtesy switch circuit

Harness or connector

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If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

After a wireless door lock operation is performed with the back door open, the theft deterrent system is not set when the back door is closed

Proceed to "Security Indicator Light Does not Blink"

IG signal circuit

Door unlock detection switch circuit

Front door courtesy switch circuit

Back door courtesy switch circuit

Engine hood courtesy switch circuit

Harness or connector

-

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

After a wireless door lock operation is performed with the engine hood open, the theft deterrent system is not set when the engine hood is closed

Proceed to "Security Indicator Light Does not Blink"

IG signal circuit

Door unlock detection switch circuit

Front door courtesy switch circuit

Back door courtesy switch circuit

Engine hood courtesy switch circuit

Harness or connector

-

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

Security indicator light does not blink when theft deterrent system is set

Proceed to "Security Indicator Light Does not Blink"

The theft deterrent system becomes set by itself

Front door courtesy switch circuit

Back door courtesy switch circuit

Engine hood courtesy switch circuit

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The theft deterrent system cannot be canceled by turning the ignition switch to ON

Main body ECU (multiplex network body ECU)

None of the alarm functions operate or the theft deterrent system can be set even when all necessary conditions are not met

Door unlock detection switch circuit

Front door courtesy switch circuit

Back door courtesy switch circuit

Engine hood courtesy switch circuit

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The theft deterrent system cannot be canceled by unlocking doors using the mechanical key (for the vehicles displaying the item "Security control with mechanism key" on the GTS)

Check power door lock control system operation

Main body ECU (multiplex network body ECU)

The doors are not forcibly locked when the vehicle is in the alarm sounding state

Entry and start system (for Entry Function)

Wireless door lock control system

Door unlock detection switch circuit

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The vehicle does not enter the alarm sounding state when the auxiliary battery is reconnected while the vehicle is in the armed state

Check operation of the security indicator light

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The vehicle does not enter the alarm sounding state when the back door is opened while the vehicle is in the armed state

Check operation of the security indicator light

Back door courtesy switch circuit

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The vehicle does not enter the alarm sounding state when the engine hood is opened while the vehicle is in the armed state

Check operation of the security indicator light

Engine hood courtesy switch circuit

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The vehicle does not enter the alarm sounding state when the doors are unlocked while the vehicle is in the armed state

Door unlock detection switch circuit

Front door courtesy switch circuit

Back door courtesy switch circuit

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The security horn assembly does not operate when the vehicle is in the alarm sounding state

Security horn circuit

The hazard warning lights do not operate when the vehicle is in the alarm sounding state

Lighting system (EXT)

Meter/gauge system

If the symptom(s) still occur after the above area is inspected and proved to be normal, replace the main body ECU (multiplex network body ECU)

The vehicle horn does not operate when the vehicle is in the alarm sounding state

Horn circuit