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 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 for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1771 is output, perform troubleshooting for the DTC.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
* If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to access 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 damage the seat or deform the seat rails. Hold the seat only as necessary.

PROCEDURE

1. CHECK CONNECTORS

(a) Turn the engine switch off.

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

(c) Check that the connectors are properly connected to the occupant classification 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 classification 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 WIRE 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 engine switch on (IG).

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

Standard Voltage:





Text in Illustration





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

3. CHECK FRONT SEAT WIRE RH (OPEN)

(a) Turn the engine switch off.





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

(c) Using SST, connect terminals 1 (RBE-) and 2 (RBE+) of connector C.

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

SST : 09843-18040

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

Standard Resistance:





Text in Illustration





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

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

(a) Disconnect SST from connector C.





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

Standard Resistance:





Text in Illustration





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

5. CHECK FRONT SEAT WIRE RH (SHORT)

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





Standard Resistance:





Text in Illustration





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

6. CHECK DTC

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

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

(c) Turn the engine switch on (IG).

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

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

(f) Turn the engine switch off.

(g) Turn the engine switch on (IG).

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

OK:

DTC B1771 is not output.

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

NG -- INSPECT FRONT SEAT INNER BELT ASSEMBLY RH

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

7. INSPECT FRONT SEAT INNER BELT ASSEMBLY RH

(a) Turn the engine switch off.

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

(c) Replace the front seat inner belt assembly RH with a known good part Removal.

HINT
Perform an inspection using known good parts from another vehicle if possible.

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

(e) Turn the engine switch on (IG).

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

(g) Clear the DTCs stored in the center airbag sensor assembly Reading and Clearing Diagnostic Trouble Codes.

(h) Turn the engine switch off.

(i) Turn the engine switch on (IG).

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

OK:

DTC B1771 is not output.

HINT
Codes other than 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) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Using the Techstream, save the ECU data from the ECU currently installed on the vehicle Registration.

(d) Turn the engine switch off.

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

(f) Replace the occupant classification ECU Removal.

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

(h) Turn the engine switch on (IG).

(i) Using the Techstream, load the previous ECU data stored into the new ECU Registration.

(j) Turn the engine switch off.

(k) Turn the engine switch on (IG).

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

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

NEXT -- Continue to next step.

9. PERFORM SENSITIVITY CHECK

(a) Perform the sensitivity check Initialization.

NEXT -- END