DTC B1794: Open in Occupant Classification ECU Battery Positive Line: Procedure

1. Measure the voltage of the battery.

   Standard Voltage

   11 to 14 V

NG → REPLACE BATTERY 

OK: Go to next step 

1. Turn the engine switch off.
   Fig 1: Z4 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the cable from the negative (-) battery terminal.
3. Disconnect the connector from the occupant classification 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
   Z4-1 (+B) - Body ground	Always	11 to 14 V
   Z4-7 (IG) - Body ground	Engine switch on (IG)	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
   Z4-3 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Occupant Classification ECU)

NG → REPLACE WIRE HARNESS 

OK: Go to next step 

1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal.
3. Connect the connector to the occupant classification ECU.
4. Connect the Techstream to the DLC3.
5. Connect the cable to the negative (-) battery terminal.
6. Turn the engine switch on (IG).
7. Clear the DTCs stored in the occupant classification ECU. Refer to DTC CHECK / CLEAR .
8. Clear the DTCs stored in the center airbag sensor assembly. Refer to DTC CHECK / CLEAR .
9. Turn the engine switch off.
10. Turn the engine switch on (IG), and wait for at least 10 seconds.
11. Using the Techstream, check for DTCs of the occupant classification ECU. Refer to DTC CHECK / CLEAR .

    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.

NG → See step   4 

OK → See step   7 

1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal.
3. Replace the occupant classification ECU. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the cable to the negative (-) battery terminal.
2. Connect the Techstream to the DLC3.
3. Turn the engine switch on (IG).
4. Using the Techstream, perform Zero Point Calibration. Refer to INITIALIZATION .

   OK

   "Zero Point Calibration is complete." is displayed.

NEXT: Go to next step 

1. Using the Techstream, perform Sensitivity Check. Refer to INITIALIZATION .

   Standard

   27 to 33 kg (59.5 to 72.8 lb)

NEXT → END