B1771

SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1771: Passenger Side Buckle Switch Circuit Malfunction
B1771 - Passenger Side Buckle Switch Circuit Malfunction

DESCRIPTION

The passenger side buckle switch circuit consists of the occupant classification ECU and the front seat inner belt assembly RH.

DTC B1771 is stored when a malfunction is detected in the passenger side buckle switch circuit.





HINT
* When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1771 of the occupant classification system.
* Use the Techstream to check for DTCs of the occupant classification ECU, otherwise the DTC cannot be read.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
* If troubleshooting (wire harness inspection) is difficult to perform, remove the front seat assembly RH installation bolts to see the undersurface of the seat cushion.
* In the above case, hold the seat so that it does not fall down. Holding the seat for a long period of time may cause a problem, such as seat rail deformation. Hold the seat up only for as long as necessary.

PROCEDURE

1. CHECK FOR DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Clear the DTCs stored in the memory Reading and Clearing Diagnostic Trouble Codes.

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.

(c) Turn the ignition switch off.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1771 is not output.

HINT
Codes other than DTC B1771 may be output at this time, but they are not related to this check.

NG -- CHECK CONNECTION OF CONNECTOR

OK -- USE SIMULATION METHOD TO CHECK Diagnosis System

2. CHECK CONNECTION OF CONNECTOR

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

(c) Check that the connectors are properly connected to the occupant classification ECU and the front seat inner belt assembly RH.

OK:

Connectors are properly connected.

NG -- CONNECT CONNECTORS PROPERLY
OK -- Continue to next step.

3. CHECK CONNECTOR

(a) Disconnect the connectors from the occupant classification ECU and the front seat inner belt assembly RH.

(b) Check that the connectors (on the occupant classification ECU side and front seat inner belt assembly RH side) are not damaged.

OK:

Connectors are not deformed or damaged.

NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.

4. CHECK FRONT SEAT WIRE RH





Text in Illustration





(a) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





(d) Turn the ignition switch off.

(e) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

(f) Using a service wire, connect terminals 1 (RBE+) and 2 (RBE-) of connector C.

NOTICE:
Do not forcibly insert the service wire into the terminals of the connector.

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

Standard Resistance:





(h) Disconnect the service wire from connector C.

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

Standard Resistance:





NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.

5. CHECK FOR DTC

(a) Connect the connectors to the occupant classification ECU and the front seat inner belt assembly RH.

(b) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

(c) Turn the ignition switch to ON, and wait for at least 60 seconds.

(d) Clear the DTCs stored in the memory Reading and Clearing Diagnostic Trouble Codes.

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.

(e) Turn the ignition switch off.

(f) Turn the ignition switch to ON, and wait for at least 60 seconds.

(g) Using the Techstream, check for DTCs of the occupant classification ECU Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1771 is not output.

HINT
DTCs other than DTC B1771 may be output at this time, but they are not related to this check.

NG -- REPLACE FRONT SEAT INNER BELT ASSEMBLY RH (PASSENGER SIDE BUCKLE SWITCH)

OK -- USE SIMULATION METHOD TO CHECK Diagnosis System

6. REPLACE FRONT SEAT INNER BELT ASSEMBLY RH (PASSENGER SIDE BUCKLE SWITCH)

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

(c) Replace the front seat inner belt assembly RH Removal.

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

(d) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

NEXT -- Continue to next step.

7. CHECK FOR DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Clear the DTCs stored in the memory Reading and Clearing Diagnostic Trouble Codes.

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.

(c) Turn the ignition switch off.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Using the Techstream, check for DTCs of the occupant classification ECU Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1771 is not output.

HINT
DTCs other than DTC B1771 may be output at this time, but they are not related to this check.

NG -- REPLACE OCCUPANT CLASSIFICATION ECU

OK -- END

8. REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

(c) Replace the occupant classification ECU Removal.

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

(d) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

(e) Turn the ignition switch to ON, and wait for at least 60 seconds.

(f) Clear the DTCs stored in the memory Reading and Clearing Diagnostic Trouble Codes.

HINT
If the DTCs are not cleared at this time, past DTCs will remain.

NEXT -- Continue to next step.

9. PERFORM ZERO POINT CALIBRATION

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Using the Techstream, perform the zero point calibration Programming and Relearning.

NEXT -- Continue to next step.

10. PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check Programming and Relearning.

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

NEXT -- END