Toyota Yaris: Airbag System / System Description
SYSTEM DESCRIPTION
FUNCTION OF SRS CONNECTORS
(a) Location of activation prevention mechanism
(b) Function of activation prevention mechanism
(1) This mechanism is designed to create a short circuit automatically between the positive (+) and negative (-) terminals of a squib power source connector when disconnected.
(2) The short spring contained in the connector creates a closed circuit on the squib side (no potential difference can occur between both terminals), preventing accidental squib deployment when servicing.
(c) Releasing of activation prevention mechanism
(1) To release the activation prevention mechanism, insert a piece of paper with the same thickness as the male terminal (approximately 0.5 mm (0.0197 in.)) between the terminals and short spring to break the connection.
(2) Refer to the following illustrations concerning connectors utilizing the activation prevention mechanism and its release method.
CAUTION:
Never release the activation prevention mechanism on the squib connector even when inspecting with the squib disconnected.
NOTICE:
-
Do not release the activation prevention mechanism unless specified by the troubleshooting procedure.
-
To prevent the terminals and short spring from being damaged, always use a piece of paper with the same thickness as the male terminal.
HINT:
To prevent improper operation due to static electricity, etc., the connector of the SRS airbag squib circuit has a short mechanism, and the airbag terminal is shorted while the connector is disconnected.

SYSTEM DIAGRAM
Communication Table Transmitting ECU / Parts (Transmitter) Receiving ECU / Parts (Receiver) Signal Communication Method Front Airbag Sensor Airbag Sensor Assembly
Front collision G signal
Direct line No...
CAUTION / NOTICE / HINT HINT:
Use the following procedure to troubleshoot the airbag system.
*: Use the GTS.
PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP
NEXT
2...
Other information:
Commander switch
Audio control switch
Volume adjustment
Turn the commander switch volume dial. The volume switch on the
steering switch can also be pressed.
Press the volume dial to mute and pause. However, while an audio
source which cannot be paused such as FM radio is playing, only mute
is available...
TERMINALS OF ECU CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
(a) Disconnect the H46 certification ECU (smart key ECU assembly) connector. (b) Measure the voltage and resistance according to the value(s) in the table below. Tester Connection Terminal Description Condition Specified Condition Related Data List Item H46-29 (E) - Body ground Ground Always Below 1 Ω - H46-6 (+B) - H46-29 (E) Power supply Always 11 to 14 V - H45-22 (CUTB) - H46-29 (E) Dark current cut pin* Ignition switch off 11 to 14 V -
*: In order to prevent the vehicle auxiliary battery from being depleted when the vehicle is shipped long distances, a fuse that cuts unnecessary electrical load while the vehicle is being shipped is installed in the circuit...