Toyota Sienna Service Manual: Sleep Operation Failure of Occupant Classification ECU

DTC B1796 Sleep Operation Failure of Occupant Classification ECU

DESCRIPTION

During sleep mode, the occupant classification ECU reads 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 output.

INSPECTION PROCEDURE

1 CHECK DTC

1. Turn the ignition switch to the ON position.
2.  Clear the DTCs stored in memory.

   HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.

3.  Turn the ignition switch to the LOCK position.
4.  Turn the ignition switch to the ON position.
5.  Check the DTCs.

OK: DTC B1796 is not output.

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

2 REPLACE OCCUPANT CLASSIFICATION ECU

1. Turn the ignition switch to the LOCK position.
2.  Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3.  Replace the occupant classification ECU

3 PERFORM ZERO POINT CALIBRATION

1. Connect the negative (-) terminal cable to the battery.
2.  Connect the intelligent tester to the DLC3.
3.  Turn the ignition switch to the ON position.
4.  Using the intelligent tester, perform "Zero point calibration".

OK: The "COMPLETED" is displayed.

4 PERFORM SENSITIVITY CHECK

1. Using the intelligent tester, perform "Sensitivity check".

Standard values: 27 to 33 kg (59.52 to 72.75 lb)

END