General Information

Weight Classification
B1644 CAN time-out ACU - General Information

Component Location





General Description

In contrast to the initial one-stage airbag systems, newer restraint systems involve complex logic to select, or alternatively suppress, various levels of safety system deployment.
Inherent to an advanced Restraint System is the ability to discern information regarding passenger occupancy.
It is intended that these inputs be provided through the weight measuring OC system.
The object of such safety system is to reduce the risk and level of injuries by automatically adapting the airbag(s) and seat belt pretensioner to the driving status of the vehicle, its occupants, and the crash severity.
The current OC system covered in this specification continually senses and classifies the front passenger side seat.
OCS is utilizing a robust weight measuring technology. Thus, if any of the following conditions occur, 'command zero' and 'accuracy check' should be performed after checking WCS Diagnostic Codes.
The weight classification ECU or any of the sensors is replaced.
The vehicle is brought to the repair shop due to an accident or a crash even though the severity seems to be minor.
The passenger airbag ON indicator is not illuminated when the passenger seat is not occupied.
The passenger airbag ON indicator is delayed more than 10 seconds to be turned off when an adult passenger seats in.
The passenger seat is removed from the vehicle and re-assembled.
Any accessories (side table, seatback table and seat cover, etc) are replaced or installed.

DTC Description

This code is outputted when WCS can't receive data from SRSCM by CAN Line for 10 sec.

DTC Detecting Condition





Diagnostic Circuit Diagram





Signal Waveform & Data




Fig.1) CAN Low/High Signal Waveform