DTC B1794: Open in Occupant Classification ECU Battery Positive Line [07/2015 - ]: Procedure

1. Measure the voltage of the battery.

   Standard Voltage

   11 to 14 V

Result:  NG

NG 

INSPECT CHARGING SYSTEM AND BATTERY 

(Refer to ON-VEHICLE INSPECTION [07/2015 - ] )

Result:  OK

OK 

See step  2

1. Turn the engine switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   W23-1 (+B) - Body ground	Always	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   W23-3 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

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

Result:  NG

NG 

REPLACE WIRE HARNESS 

Result:  OK

OK 

See step  3

1. Disconnect the cable from the negative (-) battery terminal.
2. Connect the connector to the occupant detection ECU.
3. Connect the cable to the negative (-) battery terminal.
4. Clear the DTCs stored in the occupant detection ECU (Refer to DTC CHECK / CLEAR [07/2015 - ] ).
5. Clear the DTCs stored in the airbag sensor assembly (Refer to DTC CHECK / CLEAR [07/2015 - ] ).
6. Turn the engine switch off.
7. Turn the engine switch on (IG), and wait for at least 10 seconds.
8. Check for DTCs (Refer to DTC CHECK / CLEAR [07/2015 - ] ).

   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 engine switch off.

Result:  OK

OK 

USE SIMULATION METHOD TO CHECK 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [07/2015 - ] )

Result:  NG

NG 

See step  4

1. Disconnect the cable from the negative (-) battery terminal.
2. Replace the occupant detection ECU (Refer to REMOVAL [07/2015 - ] ).
3. Connect the cable to the negative (-) battery terminal.

Result:  NEXT

NEXT 

See step  5

1. Using the Techstream, perform Zero Point Calibration and Sensitivity Check (Refer to INITIALIZATION [07/2015 - ] ).

Result:  NEXT

NEXT 

END