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 → See step   6 

OK: Go to next step 

1. Turn the engine switch off.
   Fig 1: Measuring Voltage Of Wire Harness (Source Voltage) Connector

   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
   R3-1 (+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
   R3-3 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

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

NG → REPLACE WIRE HARNESS 

OK: Go to next step 

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 .
5. Clear the DTCs stored in the airbag ECU assembly. Refer to DTC CHECK / CLEAR .
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 .

   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.

NG → See step   4 

OK → See step   7 

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

NEXT: Go to next step 

1. Using the Techstream, perform Zero Point Calibration and Sensitivity Check. Refer to INITIALIZATION .

NEXT → END