SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1796; Sleep Operation Failure of Occupant Classification ECU; 2016 - 2020 MY Sienna [12/2015

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM100000000VJSA
Model Year Start: 2016	Model: Sienna	Prod Date Range: [12/2015 - ]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1796; Sleep Operation Failure of Occupant Classification ECU; 2016 - 2020 MY Sienna [12/2015 - ]

DTC

B1796

Sleep Operation Failure of Occupant Classification ECU

DESCRIPTION

During sleep mode, the occupant classification ECU monitors the condition of each sensor while the ignition switch is off. In this mode, if the occupant classification ECU detects an internal malfunction, DTC B1796 is stored.

DTC Code	DTC Detection Condition	Trouble Area
B1796	Occupant classification ECU malfunction	Occupant classification ECU

HINT:

When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1796 of the occupant classification system.
Use the Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

PROCEDURE

1.	CHECK FOR DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Clear any DTCs stored in the memory (See page ).

HINT:

First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Using the Techstream, check for DTCs of the occupant classification ECU (See page ).

OK:

DTC B1796 is not output.

HINT:

DTCs other than DTC B1796 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

2.	REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

HINT:

Perform the inspection using parts from a normal vehicle when possible.

3.	PERFORM ZERO POINT CALIBRATION

(a) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

(b) Connect the Techstream to the DLC3.

(d) Using the Techstream, perform the zero point calibration (See page ).

4.	PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check (See page ).

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

END