B1785

SUPPLEMENTAL RESTRAINT SYSTEM: OCCUPANT CLASSIFICATION SYSTEM (for Separate Seat Type): B1785: Front Occupant Classification Sensor LH Collision Detection

DTC B1785 - Front Occupant Classification Sensor LH Collision Detection

DESCRIPTION

DTC B1785 is set when the occupant classification ECU receives a collision detection signal, which is sent by the occupant classification sensor front LH when an accident occurs.
DTC B1785 is also set when the front seat with adjuster frame assembly 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 is not in a collision, DTC B1785 can be cleared by conducting the zero point calibration and sensitivity check.
Therefore, if DTC B1785 is set, first perform the zero point calibration and sensitivity check.





HINT:
- When DTC B1650/32 is set as a result of troubleshooting the supplemental restraint 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

PROCEDURE

1. CHECK DTC
(a) Turn the ignition switch to the ON position.
(b) Clear any DTCs stored in the center airbag sensor assembly Occupant Classification System (for Separate Seat Type).
(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 B1785 is not output.
HINT: DTCs other than B1785 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.

2. PERFORM ZERO POINT CALIBRATION
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) 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.

3. 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.

4. CHECK DTC
(a) Turn the ignition switch to the ON position.
(b) Clear any DTCs stored in the center airbag sensor assembly Occupant Classification System (for Separate Seat Type).
(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 B1785 is not output.
HINT: DTCs other than B1785 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.

5. 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.
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 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 OCCUPANT CLASSIFICATION ECU
OK -- Continue to next step.

7. PERFORM SENSITIVITY CHECK
(a) Using the Techstream, perform the sensitivity check Occupant Classification System (for Separate Seat Type).
Standard :
27 to 33 kg (59.52 to 72.75 lb)
NG -- REPLACE OCCUPANT CLASSIFICATION ECU
OK -- Continue to next step.

8. 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 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 B1785 is not output.
HINT: DTCs other than B1785 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.
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.
NEXT -- Continue to next step.

11. PERFORM SENSITIVITY CHECK
(a) Using the Techstream, perform the sensitivity check Occupant Classification System (for Separate Seat Type).
Standard:
27 to 33 kg (59.52 to 72.75 lb)
NEXT -- USE SIMULATION METHOD TO CHECK