B1780
SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1780: Front Occupant Classification Sensor LH Circuit Malfunction
B1780 - Front Occupant Classification Sensor LH Circuit Malfunction
DESCRIPTION
The front occupant classification sensor LH circuit consists of the occupant classification ECU and front occupant classification sensor LH.
DTC B1780 is stored when a malfunction is detected in the front occupant classification sensor LH circuit.
HINT
- When DTC B1650/32 is stored as a result of troubleshooting the airbag 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 DTCs cannot be read.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
- If troubleshooting (wire harness inspection) is difficult to perform, remove the front seat 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 problems, 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 memory Reading and Clearing Diagnostic Trouble Codes.
HINT
- First clear the DTCs stored in the occupant classification ECU, and then clear the DTCs stored in the center airbag sensor.
- 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 B1780 is not output.
HINT
DTCs other than DTC B1780 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 front occupant classification sensor LH.
OK:
Connectors are properly connected.
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
3. CHECK CONNECTOR
(a) Disconnect the connectors from the occupant classification ECU and front occupant classification sensor LH.
(b) Check that the connectors (on the occupant classification ECU side and front occupant classification sensor LH side) are not damaged Electronic Circuit Inspection Procedure.
OK:
Connectors are not deformed or damaged.
NG -- REPLACE FRONT SEAT WIRE RH
OK -- Continue to next step.
4. CHECK FRONT SEAT WIRE RH
(a) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
(c) Turn the ignition switch off.
(d) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
(e) Using service wires, connect terminals 1 (SVC1) and 3 (SGD1), and terminals 2 (SIG1) and 3 (SGD1) of connector C.
NOTICE:
Do not forcibly insert the service wires into the terminals of the connector.
(f) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(g) Disconnect the service wires from connector C.
(h) 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 FOR DTC
(a) Connect the connectors to the occupant classification ECU and front occupant classification sensor LH.
(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 any DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.
HINT
- First clear the DTCs stored in the occupant classification ECU, and then clear the DTCs stored in the center airbag sensor.
- 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 B1780 is not output.
HINT
DTCs 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 Diagnosis System
6. 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.
NEXT -- Continue to next step.
7. PERFORM ZERO POINT CALIBRATION
(a) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
(b) Turn the ignition switch to ON, and wait for at least 60 seconds.
(c) Using the Techstream, perform the zero point calibration Programming and Relearning.
OK:
"Zero Point Calibration is complete." is displayed.
NG -- REPLACE SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY RH
OK -- Continue to next step.
8. 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)
NG -- REPLACE SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY RH
OK -- Continue to next step.
9. CHECK FOR DTC
(a) Clear the DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.
HINT
- First clear the DTCs stored in the occupant classification ECU, and then clear the DTCs stored in the center airbag sensor.
- Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
(b) Turn the ignition switch off.
(c) Turn the ignition switch to ON, and wait for at least 60 seconds.
(d) Using the Techstream, check for DTCs of the occupant classification ECU Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B1780 is not output.
HINT
DTCs other than DTC B1780 may be output at this time, but they are not related to this check.
NG -- REPLACE SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY RH
OK -- END
10. REPLACE SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY RH
(a) Turn the ignition switch off.
(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
(c) for Manual Seat:
(1) Replace the separate type front seat cushion spring RH Disassembly.
(d) for Power Seat:
(1) Replace the separate type front seat cushion spring RH Disassembly.
HINT
Perform the inspection using parts from a normal vehicle when possible.
NEXT -- Continue to next step.
11. PERFORM ZERO POINT CALIBRATION
(a) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
(b) Turn the ignition switch to ON, and wait for at least 60 seconds.
(c) Using the Techstream, perform the zero point calibration Programming and Relearning.
OK:
"Zero Point Calibration is complete." is displayed.
NEXT -- Continue to next step.
12. 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