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.
DTC No. |
DTC Detecting Condition |
Trouble Area |
B1795 |
- Occupant classification ECU circuit malfunction
- The occupant classification ECU receives a short
circuit to ground signal in the passenger side
buckle switch circuit for 2 seconds.
- Occupant classification ECU malfunction
|
- Front seat wire RH
- Front seat inner belt assembly RH (Passenger side
buckle switch)
- Occupant classification ECU
|
INSPECTION PROCEDURE
1 CHECK DTC
- Turn the ignition switch to the ON position, and wait for at
least 10 seconds.
- 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
- Measure the resistance of the ECU-B fuse.
Resistance:
Below 1 Ω
3 CHECK WIRE HARNESS (SOURCE VOLTAGE)

- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Disconnect the connector from the occupant
classification ECU.
- Connect the negative (-) terminal cable to the battery.
- Turn the ignition switch to the ON position.
- Measure the voltage according to the value(s) in the
table below.
Standard voltage

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

4 REPLACE OCCUPANT CLASSIFICATION ECU
- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Replace the occupant classification ECU
5 PERFORM ZERO POINT CALIBRATION
- Connect the negative (-) terminal cable to the battery.
- Connect the intelligent tester to the DLC3.
- Turn the ignition switch to the ON position.
- Using the intelligent tester, perform "Zero point
calibration" (28).
OK:
"COMPLETED" is displayed.
6 PERFORM SENSITIVITY CHECK
- Using the intelligent tester, perform "Sensitivity check"
(28).
Standard value:
27 to 33 kg (59.52 to 72.75 lb)
END
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 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 of ...
Other materials:
Under hood
GENERAL MAINTENANCE
1. GENERAL NOTES
Maintenance requirements very depending on the
country.
Check the maintenance schedule in the owner's
manual supplement.
Following the maintenance schedule is mandatory.
Determine the appropriate time to service the vehicle
using either miles dri ...
Engine unit
COMPONENTS
...
High Temperature
DTC 44-47 High Temperature
DESCRIPTION
DTC No.
DTC Detecting Condition
Trouble Area
44-47
Sensor detects that DVD unit temperature is high.
(Over 80C)
Television display assembly
INSPECTION PROCEDURE
HINT:
After the inspection is completed, ...