B1780
SUPPLEMENTAL RESTRAINT SYSTEM: OCCUPANT CLASSIFICATION SYSTEM: B1780: Front Occupant Classification Sensor LH Circuit Malfunction
DTC B1780 - Front Occupant Classification Sensor LH Circuit Malfunction
DESCRIPTION
The front occupant classification sensor LH circuit consists of the occupant classification ECU and the front occupant classification sensor LH.
DTC B1780 is recorded when a malfunction is detected in the front occupant classification sensor LH 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 B1780 in 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 see under the seat cushion.
- In the above case, 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 negative (-) terminal cable from the battery.
(c) Check that the connectors are properly connected to the occupant classification ECU and the 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 the 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 negative (-) terminal cable to the battery.
(b) Turn the ignition switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.
3. CHECK FRONT SEAT WIRE RH (OPEN)
(a) Turn the ignition switch off.
(b) Disconnect the negative (-) terminal cable from the battery.
(c) Using SST, connect terminals 1 (SVC1) and 3 (SGD1), and connect terminals 2 (SIG1) and 3 (SGD1) of connector C.
NOTE: Do not forcibly insert SST into the terminals of the connector when connecting.
SST: 09843-18040
(d) 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.
4. CHECK FRONT SEAT WIRE RH (SHORT)
(a) Disconnect SST from connector C.
(b) 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 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 WIRE RH
OK -- Continue to next step.
6. CHECK DTC
(a) Connect the connectors to the occupant classification ECU and the front occupant classification sensor LH.
(b) Connect the negative (-) terminal cable to the battery.
(c) Turn the ignition switch on (IG).
(d) Clear the DTCs stored in the occupant classification ECU.
(e) Clear the DTCs stored in the center airbag sensor assembly.
(f) Turn the ignition switch off.
(g) Turn the ignition switch on (IG).
(h) Check for DTCs.
OK:
DTC B1780 is not output.
HINT: Codes other than DTC B1780 may be output at this time, but they are not related to this check.
NG -- REPLACE OCCUPANT CLASSIFICATION ECU
OK -- USE SIMULATION METHOD TO CHECK
7. REPLACE OCCUPANT CLASSIFICATION ECU
(a) Turn the ignition switch off.
(b) Disconnect the negative (-) terminal cable from the battery.
(c) Replace the occupant classification ECU.
HINT: Perform the inspection using parts from a normal vehicle if possible.
NEXT -- Continue to next step.
8. PERFORM ZERO POINT CALIBRATION
(a) Connect the negative (-) terminal cable to the battery.
(b) Connect Techstream to the DLC3.
(c) Turn the ignition switch on (IG).
(d) Using Techstream, perform "zero point calibration". Programming and Relearning
OK:
"Zero Point Calibration is complete." is displayed.
NG -- REPLACE FRONT SEAT ASSEMBLY RH
OK -- Continue to next step.
9. PERFORM SENSITIVITY CHECK
(a) Using Techstream, perform "sensitivity check". Programming and Relearning
Standard:
27 to 33 kg (59.52 to 72.75 lb)
NG -- REPLACE FRONT SEAT ASSEMBLY RH
OK -- Continue to next step.
10. CHECK DTC
(a) Turn the ignition switch on (IG).
(b) Clear the DTCs stored in the occupant classification ECU.
(c) Clear the DTCs stored in the center airbag sensor assembly.
(d) Turn the ignition switch off.
(e) Turn the ignition switch on (IG).
(f) Check for DTCs.
OK:
DTC B1780 is not output.
HINT: Codes other than DTC B1780 may be output at this time, but they are not related to this check.
NG -- REPLACE FRONT SEAT ASSEMBLY RH
OK -- END
11. REPLACE FRONT SEAT ASSEMBLY RH
(a) Turn the ignition switch off.
(b) Disconnect the negative (-) terminal cable from the battery.
(c) Replace the front seat assembly RH (Front Seat Assembly (for Power Seat) for power seat or Front Seat Assembly (for Manual Seat) for manual seat).
NEXT -- Continue to next step.
12. PERFORM ZERO POINT CALIBRATION
(a) Connect the negative (-) terminal cable to the battery.
(b) Connect Techstream to the DLC3.
(c) Turn the ignition switch on (IG).
(d) Using Techstream, perform "zero point calibration". Programming and Relearning
OK:
"Zero Point Calibration is complete." is displayed.
NEXT -- Continue to next step.
13. PERFORM SENSITIVITY CHECK
(a) Using Techstream, perform "sensitivity check". Programming and Relearning
Standard:
27 to 33 kg (59.52 to 72.75 lb)
NEXT -- END