B1780

SUPPLEMENTAL RESTRAINT SYSTEM: OCCUPANT CLASSIFICATION SYSTEM (for Separate Seat Type): B1780: Front Occupant Classification Sensor LH Circuit Malfunction
B1780 - Front Occupant Classification Sensor LH Circuit Malfunction

DESCRIPTION

The occupant classification sensor front LH circuit consists of the occupant classification ECU and the occupant classification sensor front LH.

DTC B1780 is set when a malfunction is detected in the occupant classification sensor front LH circuit.





HINT
* When DTC B1650/32 is detected as a result of troubleshooting the supplemental restraint system, perform troubleshooting for DTC B1780 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 RH seat assembly installation bolts to see the under surface 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 problems, such as seat rail deformation. Hold the seat up only for as long as necessary.

PROCEDURE

1. CHECK DTC

(a) Turn the ignition switch to the ON position.

(b) Clear any DTCs stored in the memory Occupant Classification System (for Separate Seat Type).

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 to the LOCK position.

(d) Turn the ignition switch to the ON position.

(e) Using the Techstream, check for DTCs of the occupant classification ECU Occupant Classification System (for Separate Seat Type).

OK:

DTC B1780 is not output.

HINT
DTCs other than B1780 may be output at this time, but they are not related to this check.

OK -- PERFORM SENSITIVITY CHECK
NG -- Continue to next step.

2. CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition switch to the LOCK position.

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

(c) Check that the connectors are properly connected to the occupant classification ECU and the occupant classification sensor front LH.

OK:

The connectors are properly connected.

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

3. CHECK CONNECTORS

(a) Check that the connectors (on the occupant classification ECU side and occupant classification sensor front LH side) are not damaged Electronic Circuit Inspection Procedure.

OK:

The connectors are not deformed or damaged.

NG -- REPAIR OR REPLACE WIRE HARNESS
OK -- Continue to next step.

4. CHECK NO. 1 SEAT WIRE (TO B+)

(a) Disconnect the connectors from the occupant classification ECU and the occupant classification sensor front LH.





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

(c) Turn the ignition switch to the ON position.

(d) Measure the voltage.

Standard voltage:





NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- Continue to next step.

5. CHECK NO. 1 SEAT WIRE (FOR OPEN)

(a) Turn the ignition switch to the LOCK position.





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

(c) Using service wires, connect O6-1 (SVC1) and O6-3 (SGD1), and connect O6-2 (SIG1) and O6-3 (SGD1) of connector C.

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

(d) Measure the resistance.

Standard resistance:





NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- Continue to next step.

6. CHECK NO. 1 SEAT WIRE (FOR SHORT)

(a) Disconnect the service wires from connector C.





(b) Measure the resistance.

Standard resistance:





NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- Continue to next step.

7. CHECK NO. 1 SEAT WIRE (TO GROUND)





(a) Measure the resistance.

Standard resistance:





NG -- REPAIR OR REPLACE NO. 1 SEAT WIRE
OK -- Continue to next step.

8. CHECK DTC

(a) Connect the connectors to the occupant classification ECU and the occupant classification sensor front LH.

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

(c) Turn the ignition switch to the ON position.

(d) Clear any DTCs stored in the memory Occupant Classification System (for Separate Seat Type).

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 to the LOCK position.

(f) Turn the ignition switch to the ON position.

(g) Using the Techstream, check for DTCs of the occupant classification ECU Occupant Classification System (for Separate Seat Type).

OK:

DTC B1780 is not output.

HINT
DTCs other than B1780 may be output at this time, but they are not related to this check.

OK -- USE SIMULATION METHOD TO CHECK
NG -- Continue to next step.

9. REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the ignition switch to the LOCK position.

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

NEXT -- Continue to next step.

10. PERFORM ZERO POINT CALIBRATION

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

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to the ON position.

(d) Using the Techstream, perform the zero point calibration Occupant Classification System (for Separate Seat Type).

OK:

"Zero Point Calibration is complete." is displayed on the Techstream.

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

11. PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check Occupant Classification System (for Separate Seat Type).

Standard value:

27 to 33 kg (59.52 to 72.75 lb)

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

12. CHECK DTC

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

(b) Turn the ignition switch to the ON position.

(c) Clear any DTCs stored in the memory Occupant Classification System (for Separate Seat Type).

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.

(d) Turn the ignition switch to the LOCK position.

(e) Turn the ignition switch to the ON position.

(f) Using the Techstream, check for DTCs of the occupant classification ECU Occupant Classification System (for Separate Seat Type).

OK:

DTC B1780 is not output.

HINT
DTCs other than B1780 may be output at this time, but they are not related to this check.

OK -- USE SIMULATION METHOD TO CHECK
NG -- Continue to next step.

13. REPLACE FRONT SEAT WITH ADJUSTER FRAME ASSEMBLY RH

(a) Turn the ignition switch to the LOCK position.

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

(c) Replace the front seat with adjuster frame assembly RH Removal.

NEXT -- Continue to next step.

14. PERFORM ZERO POINT CALIBRATION

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

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to the ON position.

(d) Using the Techstream, perform the zero point calibration Occupant Classification System (for Separate Seat Type).

OK:

"Zero Point Calibration is complete." is displayed on the Techstream.

NEXT -- Continue to next step.

15. PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check Occupant Classification System (for Separate Seat Type).

Standard value:

27 to 33 kg (59.52 to 72.75 lb)

NEXT -- USE SIMULATION METHOD TO CHECK