Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Toyota vehicle intrusion protection system / Horn relay circuit / Circuit description
Toyota Corolla (E120): Circuit description
When the tvip system is transferred from the armed state to the alarm sounding state, the tvip ecu switches on the horn relay so that it can sound the horns. The horn sounds in 0.4 Seconds interval.
Wiring diagram

Other materials:
Seat belts
Make sure that all occupants
are wearing their seat
belts before driving the
vehicle.
WARNING
Observe the following precautions
to reduce the risk of injury in the
event of sudden braking, sudden
swerving or an accident.
Failure to do so may cause death
or serious injury.
■Wearing a seat belt
E ...
Source voltage drop
The srs is equipped with a voltage–increase circuit (dc–dc converter) in the
airbag sensor assy center
in case the source voltage drops.
When the battery voltage drops, the voltage–increase circuit (dc–dc converter)
functions to increase the
voltage of the srs to normal voltage.
...
Inspection procedure
1 Check source voltage
Measure the voltage of the battery.
Ok:
voltage: 10 – 14 v
2 Check air bag sensor assy center
Disconnect the negative (–) terminal cable from the battery, and wait at
least for 90 seconds.
disconnect the connectors from the airbag sensor assy ...


