Toyota Sienna Service Manual: Occupant Classification ECU Malfunction

DTC B1795 Occupant Classification ECU Malfunction

DESCRIPTION

DTC B1795 is recorded when a malfunction is detected in the occupant classification ECU.

Troubleshoot DTC B1771 first when the DTCs B1771 and B1795 are output simultaneously.

INSPECTION PROCEDURE

1 CHECK DTC

1. Turn the ignition switch to the ON position, and wait for at least 10 seconds.
2.  Check the DTCs (35).

Result:
A:
DTC B1795 is output.

B:
DTCs B1771 and B1795 are output.

HINT: Codes other than DTC B1771 and B1795 may be output at this time, but they are not related to this check.

2 CHECK FUSE

1. Measure the resistance of the ECU-B fuse.

   Resistance: Below 1 Ω

3 CHECK WIRE HARNESS (SOURCE VOLTAGE)

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.  Disconnect the connector from the occupant classification ECU.
4.  Connect the negative (-) terminal cable to the battery.
5.  Turn the ignition switch to the ON position.
6.  Measure the voltage according to the value(s) in the table below.

Standard voltage

7. Turn the ignition switch to the LOCK position.
8.  Measure the resistance according to the value(s) in the table below.

Standard resistance

4 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

5 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" (28).

OK: "COMPLETED" is displayed.

6 PERFORM SENSITIVITY CHECK

1. Using the intelligent tester, perform "Sensitivity check" (28).

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

END