DTC B1794: Open in Occupant Classification ECU Battery Positive Line [11/2015 - ]: Procedure

1. Measure the voltage of the auxiliary battery.

   Standard Voltage

   11 to 14 V

Result: 

NG 

INSPECT CHARGING SYSTEM AND AUXILIARY BATTERY 

(Refer to ON-VEHICLE INSPECTION [11/2015 - 06/2017]

Result: 

OK 

See step  2

1. Turn the ignition switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Y3-1 (+B) - Body ground	Ignition switch off	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Y3-3 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Occupant Detection ECU)

Result: 

NG 

REPLACE WIRE HARNESS 

Result: 

OK 

See step  3

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Connect the connector to the occupant detection ECU.
3. Connect the cable to the negative (-) auxiliary battery terminal.
4. Clear the DTCs stored in the occupant detection ECU (Refer to DTC CHECK / CLEAR [11/2015 - ] ).
5. Clear the DTCs stored in the airbag sensor assembly (Refer to DTC CHECK / CLEAR [11/2015 - ] ).
6. Turn the ignition switch off.
7. Turn the ignition switch to ON (IG), and wait for at least 10 seconds.
8. Check for DTCs (Refer to DTC CHECK / CLEAR [11/2015 - ] ).

   OK

   DTC B1794 is not output.

   HINT: 

   Codes other than DTC B1794 may be output at this time, but they are not related to this check.

9. Turn the ignition switch off.

Result: 

OK 

USE SIMULATION METHOD TO CHECK 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2015 - ] )

Result: 

NG 

See step  4

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Replace the occupant detection ECU (Refer to REMOVAL [11/2015 - ] ).
3. Connect the cable to the negative (-) auxiliary battery terminal.

NEXT 

See step  5

1. Using the Techstream, perform Zero Point Calibration and Sensitivity Check (Refer to INITIALIZATION [11/2015 - 06/2017]

NEXT 

END