B1785

SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1785: Front Occupant Classification Sensor LH Collision Detection
B1785 - Front Occupant Classification Sensor LH Collision Detection

DESCRIPTION

DTC B1785 is stored when the occupant classification ECU receives a collision detection signal, which is sent by the front occupant classification sensor LH when an accident occurs.

DTC B1785 is also stored when the separate type front seat cushion spring RH is subjected to a strong impact, even if an actual accident has not occurred.

However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle has not been in a collision, DTC B1785 can be cleared by conducting the zero point calibration and sensitivity check.

Therefore, if DTC B1785 is output, first perform the zero point calibration and sensitivity check.





HINT
* When DTC B1650/32 is stored as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1785 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

NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.

PROCEDURE

1. CHECK FOR DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the ignition switch off.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

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

OK:

DTC B1785 is not output.

HINT
DTCs other than DTC B1785 may be output at this time, but they are not related to this check.

NG -- PERFORM ZERO POINT CALIBRATION

OK -- USE SIMULATION METHOD TO CHECK Diagnosis System

2. PERFORM ZERO POINT CALIBRATION

(a) 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.

3. PERFORM SENSITIVITY CHECK

(a) Perform the sensitivity check Programming and Relearning.

Standard:

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.

4. CHECK FOR DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the ignition switch off.

(c) Turn the ignition switch to ON, and wait for at least 60 seconds.

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

OK:

DTC B1785 is not output.

HINT
DTCs other than DTC B1785 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

5. 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) 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.

6. 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.

(c) Perform the zero point calibration Programming and Relearning.

OK:

"Zero Point Calibration is complete." is displayed.

NG -- REPLACE OCCUPANT CLASSIFICATION ECU
OK -- Continue to next step.

7. PERFORM SENSITIVITY CHECK

(a) Perform the sensitivity check Programming and Relearning.

Standard:

27 to 33 kg (59.5 to 72.8 lb)

NG -- REPLACE OCCUPANT CLASSIFICATION ECU
OK -- Continue to next step.

8. CHECK FOR DTC

(a) Clear the DTCs 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) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1785 is not output.

HINT
DTCs other than DTC B1785 may be output at this time, but they are not related to this check.

NG -- REPLACE OCCUPANT CLASSIFICATION ECU

OK -- END (SEPARATE TYPE FRONT SEAT CUSHION SPRING RH IS DEFECTIVE)

9. 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.

10. 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.

(c) Perform the zero point calibration Programming and Relearning.

OK:

"Zero Point Calibration is complete." is displayed.

NEXT -- Continue to next step.

11. PERFORM SENSITIVITY CHECK

(a) Perform the sensitivity check Programming and Relearning.

Standard:

27 to 33 kg (59.5 to 72.8 lb)

NEXT -- END (OCCUPANT CLASSIFICATION ECU IS DEFECTIVE)