Power Source Circuit: Procedure

1. Disconnect the cable from the negative (-) battery terminal.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   WARNING:

   Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

2. Disconnect the Q57 connector of the seat belt control ECU.
3. Connect the cable to the negative (-) battery terminal.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Q57-7 (+B) - Body ground	Always	10 to 14 V

5. Disconnect the cable from the negative (-) battery terminal.
6. Reconnect the Q57 connector of the seat belt control ECU.
7. Connect the cable to the negative (-) battery terminal.

NG → See step   4 

OK: Go to next step 

1. Disconnect the cable from the negative (-) battery terminal.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   WARNING:

   Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

2. Disconnect the Q58 connector of the seat belt control ECU.
3. Connect the cable to the negative (-) battery terminal.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Q58-8 (IG1) - Body ground	Engine switch on (IG)	10 to 14 V
   Q58-8 (IG1) - Body ground	Engine switch off	Below 1 V

5. Disconnect the cable from the negative (-) battery terminal.
6. Reconnect the Q58 connector of the seat belt control ECU.
7. Connect the cable to the negative (-) battery terminal.

NG → See step   5 

OK: Go to next step 

1. Disconnect the cable from the negative (-) battery terminal.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   WARNING:

   Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

2. Disconnect the Q57 connector of the seat belt control ECU.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q57-8 (PGND) - Body ground	Always	Below 1 Ω

4. Reconnect the Q57 connector of the seat belt control ECU.
5. Connect the cable to the negative (-) battery terminal.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (PGND CIRCUIT) 

OK → See step   6 

1. Remove the PSB fuse from the cowl side J/B LH.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   PSB fuse	Always	Below 1 Ω

3. Reinstall the PSB fuse to the cowl side J/B LH.

NG → REPLACE FUSE (PSB FUSE) 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (SEAT BELT CONTROL ECU - BATTERY) 

1. Remove the ECU-IG RH fuse from the cowl side J/B RH.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   ECU-IG RH fuse	Always	Below 1 Ω

3. Reinstall the ECU-IG RH fuse to the cowl side J/B RH.

NG → REPLACE FUSE (ECU-IG RH FUSE) 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (SEAT BELT CONTROL ECU - RH IG1 RELAY)