B1771

SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1771; Seat Belt Buckle SW; 2013 MY FR-S [03/2012 -]
B1771 - Seat Belt Buckle SW

DESCRIPTION

The passenger side buckle switch circuit consists of the occupant detection ECU and 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 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant detection ECU. When DTC B1771 is output, perform troubleshooting for the DTC.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Service Precautions.

HINT
* If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to see under the seat cushion.
* In the above case, lift and hold the seat so that it does not fall down. Hold the seat only as necessary because holding the seat for a long period of time may cause seat rail deformation.

PROCEDURE

1. CHECK CONNECTORS

(a) Turn the ignition switch off.

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

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

OK:

The connectors are properly connected.

HINT
If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

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

(e) Check that the terminals of the connectors are not damaged.

OK:

The terminals are not deformed or damaged.

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

2. CHECK FRONT SEAT WIRE RH (SHORT TO B+)

(a) Connect the cable to the negative (-) battery terminal.









(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.

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

3. CHECK FRONT SEAT WIRE RH (OPEN)

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









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

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

Standard Resistance:





(c) Disconnect the service wire from connector C.

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

4. CHECK FRONT SEAT WIRE RH (SHORT)

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









Standard Resistance:





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

5. CHECK FRONT SEAT WIRE RH (SHORT TO GROUND)

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









Standard Resistance:





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

6. CHECK DTC

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

(b) Connect the cable to the negative (-) battery terminal.

(c) Clear the DTCs stored in the occupant detection ECU Reading and Clearing Diagnostic Trouble Codes.

(d) Clear the DTCs stored in the airbag ECU assembly Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the ignition switch off.

(f) Turn the ignition switch to ON.

(g) 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.

(h) Turn the ignition switch off.

NG -- CHECK FRONT SEAT INNER BELT ASSEMBLY RH

OK -- USE SIMULATION METHOD TO CHECK

7. CHECK FRONT SEAT INNER BELT ASSEMBLY RH

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

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

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

(c) Connect the cable to the negative (-) battery terminal.

(d) Clear the DTCs stored in the occupant detection ECU Reading and Clearing Diagnostic Trouble Codes.

(e) Clear the DTCs stored in the airbag ECU assembly Reading and Clearing Diagnostic Trouble Codes.

(f) Turn the ignition switch off.

(g) Turn the ignition switch to ON.

(h) 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 -- REPLACE FRONT SEAT ASSEMBLY RH

OK -- END (FRONT SEAT INNER BELT ASSEMBLY RH WAS DEFECTIVE)