Toyota Sienna Service Manual: System description
1. DESCRIPTION OF OCCUPANT CLASSIFICATION SYSTEM
- GENERAL DESCRIPTION.
- In the occupant classification system, the occupant classification ECU calculates the weight of the occupant based on a signal from the occupant classification sensors. This system recognizes the occupant to be a child if it detects a weight of less than 36 kg (79.37 lb), and disables the front passenger airbag and front passenger side - side airbag.
- This system is mainly comprised of 4 occupant classification sensors that detect the load on the front passenger seat. The occupant classification ECU controls the system, and the passenger airbag ON/OFF indicator indicates the ON/OFF condition of the front passenger airbag and front passenger side - side airbag.
- OCCUPANT CLASSIFICATION SENSOR.
- The occupant classification sensors are installed on 4 brackets connecting the seat rail and seat frame. Accordingly, when load is applied to the front passenger seat by an occupant sitting in it, the occupant classification sensors register a distortion.
- DESCRIPTION FOR PASSENGER AIRBAG ON/OFF INDICATOR.
- The passenger airbag ON/OFF indicator is installed on the air conditioning control assembly. This indicator informs the driver whether the occupant classification ECU puts the front passenger airbag assembly and side airbag (front passenger side) into an active state or inactive state.
- If a malfunction occurs in the occupant classification system, "OFF" indication of the passenger airbag ON/OFF indicator and the SRS warning light will come on.
Precaution
1. INSPECTION PROCEDURE FOR VEHICLE INVOLVED
IN ACCIDENT
Perform the zero point calibration and sensitivity
check if any of the following conditions occur.
The occupant classi ...
How to proceed with
troubleshooting
The intelligent tester can be used in steps 4, 6, 8 and 9.
1 VEHICLE BROUGHT TO WORKSHOP
2 CUSTOMER PROBLEM ANALYSIS
3 PASSENGER AIRBAG ON/OFF INDICATOR CHECK
4 DTCs CHECK (Present and Past ...
Other materials:
ACIS Control Circuit
DESCRIPTION
This circuit opens and closes the Intake Air Control Valve (IACV) in response
to changes in the engine
load in order to increase the intake efficiency (ACIS: Acoustic Control
Induction System).
When the engine speed is between 0 and 4450 rpm and the throttle valve opening
angl ...
Open in Occupant Classification ECU Battery
Positive Line
DTC B1794 Open in Occupant Classification ECU Battery
Positive Line
DESCRIPTION
This circuit consists of the occupant classification ECU and the power source
circuit (battery, fuse, wire
harness).
DTC B1794 is recorded when a malfunction is detected in the occupant
classification ECU or t ...
Checking monitor status
The purpose of the monitor result (mode 06) is to allow
access to the results for on-board diagnostic monitoring tests
of specific components/systems that are not continuously
monitored. Examples are catalyst, evaporative emission
(EVAP) and thermostat.
The monitor result allows the OBD II sc ...
