B1785
SUPPLEMENTAL RESTRAINT SYSTEM: OCCUPANT CLASSIFICATION SYSTEM: B1785: Front Occupant Classification Sensor LH Collision Detection
B1785 - Front Occupant Classification Sensor LH Collision Detection
DESCRIPTION
DTC B1785 is output when the occupant classification ECU receives a collision detection signal sent by the front occupant classification sensor LH when an accident occurs.
DTC B1785 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual accident does not occur.
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 performing the zero point calibration and sensitivity check.
Therefore, when DTC B1785 is output, first perform the zero point calibration and sensitivity check.
WIRING DIAGRAM
Refer to DTC B1780 B1780.
INSPECTION PROCEDURE
PROCEDURE
1. PERFORM ZERO POINT CALIBRATION
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch to the on position.
(c) Using the Techstream, perform the zero point calibration Programming and Relearning.
OK:
COMPLETED is displayed.
NG -- REPLACE FRONT SEAT ASSEMBLY RH
OK -- Continue to next step.
2. PERFORM SENSITIVITY CHECK
(a) Using a Techstream, perform the sensitivity check Programming and Relearning.
Standard values:
27 to 33 kg (59.52 to 72.75 lb)
(1) Confirm that nothing is placed on the passenger seat.
(2) Confirm that the beginning sensor reading is within the standard range.
Standard range:
-3.2 to 3.2 kg (-7 to 7 lb)
(3) Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
(4) Confirm that the sensitivity is within the standard range.
Standard range:
27 to 33 kg (59.52 to 72.75 lb)
HINT
When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).
NG -- REPLACE FRONT SEAT ASSEMBLY RH
OK -- Continue to next step.
3. CHECK DTC
(a) Turn the ignition switch to the on position.
(b) Clear the DTCs stored in the memory Reading and Clearing Diagnostic Trouble Codes.
HINT
First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
(c) Turn the ignition switch to the lock position.
(d) Turn the ignition switch to the on position.
(e) Check the DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B1785 is not output.
HINT
Codes other than DTC B1785 may be output at this time, but they are not related to this check.
OK -- USE SIMULATION METHOD TO CHECK Diagnosis System
NG -- Continue to next step.
4. REPLACE FRONT SEAT 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 assembly RH Removal.
HINT
Perform the inspection using parts from a normal vehicle if possible.
NEXT -- Continue to next step.
5. PERFORM ZERO POINT CALIBRATION
(a) Connect the negative (-) terminal cable to the battery.
(b) Connect a Techstream to the DLC3.
(c) Turn the ignition switch to the on position.
(d) Using the Techstream, perform the zero point calibration Programming and Relearning.
OK:
COMPLETED is displayed.
NG -- REPLACE OCCUPANT CLASSIFICATION ECU
OK -- Continue to next step.
6. PERFORM SENSITIVITY CHECK
(a) Using a Techstream, perform the sensitivity check Programming and Relearning.
(1) Confirm that nothing is placed on the passenger seat.
(2) Confirm that the beginning sensor reading is within the standard range.
Standard range:
-3.2 to 3.2 kg (-7 to 7 lb)
(3) Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
(4) Confirm that the sensitivity is within the standard range.
Standard range:
27 to 33 kg (59.52 to 72.75 lb)
HINT
When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).
NG -- REPLACE OCCUPANT CLASSIFICATION ECU
OK -- Continue to next step.
7. CHECK DTC
(a) Turn the ignition switch to the on position.
(b) Clear the DTCs stored in the memory Reading and Clearing Diagnostic Trouble Codes.
HINT
First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
(c) Turn the ignition switch to the lock position.
(d) Turn the ignition switch to the on position.
(e) Check the DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B1785 is not output.
HINT
Codes other than DTC B1785 may be output at this time, but they are not related to this check.
OK -- USE SIMULATION METHOD TO CHECK Diagnosis System
NG -- Continue to next step.
8. 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.
9. PERFORM ZERO POINT CALIBRATION
(a) Connect the negative (-) terminal cable to the battery.
(b) Connect a Techstream to the DLC3.
(c) Turn the ignition switch to the on position.
(d) Using the Techstream, perform the zero point calibration Programming and Relearning.
OK:
COMPLETED is displayed.
NEXT -- Continue to next step.
10. PERFORM SENSITIVITY CHECK
(a) Using a Techstream, perform the sensitivity check Programming and Relearning.
(1) Confirm that nothing is placed on the passenger seat.
(2) Confirm that the beginning sensor reading is within the standard range.
Standard range:
-3.2 to 3.2 kg (-7 to 7 lb)
(3) Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
(4) Confirm that the sensitivity is within the standard range.
Standard range:
27 to 33 kg (59.52 to 72.75 lb)
HINT
When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).
NEXT -- END