Inspection Procedure

1. Measure the voltage of the battery.

   Standard voltage: 

   11 to 14 V 

NG: REPLACE BATTERY 

OK: Go to next step 

1. Check the ECU-B fuse.

   Standard resistance: 

   Below 1 Ω 

NG: REPLACE FUSE 

OK: Go to next step 

1. Turn the ignition switch to the LOCK position.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Disconnect the connector from the occupant classification ECU.
Fig 1: Identifying Occupant Classification ECU Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Connect the negative (-) terminal cable to the battery.
5. Turn the ignition switch to the ON position.
6. Measure the voltage and resistance according to the value(s) in the table below.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester connection	Condition	Specified condition
   O4-1 (+B) - Body ground	Ignition switch ON	10 to 14 V
   O4-7 (IG) - Body ground	Ignition switch ON	10 to 14 V

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

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester connection	Condition	Specified condition
   O3-3 (GND) - Body ground	Always	Below 1 Ω

NG: REPAIR OR REPLACE WIRE HARNESS 

OK: Go to next step 

1. Turn the ignition switch to the ON position.
2. Clear the DTCs stored in memory (See DTC CHECK / CLEAR  ).

   HINT:

   First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.

3. Turn the ignition switch to the LOCK position.
4. Turn the ignition switch to the ON position, and wait for at least 10 seconds.
5. Using Techstream, check the DTCs of the occupant classification ECU (See DTC CHECK / CLEAR  ).

   OK: 

   DTC B1794 is not output. 

   HINT:

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

NG: Go to step 5 

OK: USE SIMULATION METHOD TO CHECK 

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

   HINT:

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

NEXT: Go to next step 

1. Connect the negative (-) terminal cable to the battery.
2. Connect Techstream to the DLC3.
3. Turn the ignition switch to the ON position.
4. Using Techstream, perform the "Zero point calibration" (See INITIALIZATION  ).

   OK: 

   The "COMPLETED" is displayed. 

NEXT: Go to next step 

1. Using Techstream, perform the "Sensitivity check" (See INITIALIZATION  ).

   Standard value: 

   27 to 33 kg (59.52 to 72.75 lb) 

NEXT : END