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 ignition switch off.
   Fig 1: Checking Harness And Connector (Source Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Disconnect the front seat wire RH connector from the floor wire.
4. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
5. Turn the ignition switch to ON.
6. Measure the resistance and voltage according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   GM3-3 (GND) - Body ground	Always	Below 1 Ω

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   GM3-5 (+B) - Body ground	Always	11 to 14 V
   GM3-6 (IG) - Body ground	Ignition switch ON

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Front Seat Wire RH)

NG → REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Turn the ignition switch off.
   Fig 2: Checking Harness And Connector (Source Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Connect the front seat wire RH connector to the floor wire.
4. Disconnect the occupant classification ECU connector.
5. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
6. Turn the ignition switch to ON.
7. Measure the resistance and voltage according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   M3-3 (GND) - Body ground	Always	Below 1 Ω

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   M3-1 (+B) - Body ground	Always	11 to 14 V
   M3-7 (IG) - Body ground	Ignition switch ON

   TEXT IN ILLUSTRATION
   
   

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

NG → See step   8 

OK: Go to next step 

1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Connect the connectors to the occupant classification ECU.
4. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
5. Turn the ignition switch to ON, and wait for at least 60 seconds.
6. Clear any DTCs stored in the memory. Refer to DTC CHECK / CLEAR .

   HINT: 

   • First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
   • Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
7. Turn the ignition switch off.
8. Turn the ignition switch to ON, and wait for at least 60 seconds.
9. Using the Techstream, check for DTCs of the occupant classification ECU. Refer to DTC CHECK / CLEAR .

   OK

   DTC B1794 is not output.

   HINT: 

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

NG → See step   5 

OK → See step   9 

1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Replace the occupant classification ECU. Refer to REMOVAL .

   HINT: 

   Perform the inspection using parts from a normal vehicle when possible.

NEXT: Go to next step 

1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Using the Techstream, perform the zero point calibration. Refer to INITIALIZATION .

NEXT: Go to next step 

1. Using the Techstream, perform the sensitivity check. Refer to INITIALIZATION .

   Standard range

   27 to 33 kg (59.5 to 72.8 lb)

NEXT → END