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 if 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 "zero point calibration" and "sensitivity check".

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





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ZERO POINT CALIBRATION

(a) Connect Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Using Techstream, perform "zero point calibration" Programming and Relearning.

OK:

"Zero Point Calibration is complete." is displayed.

NG -- REPLACE FRONT SEAT WITH ADJUSTER FRAME ASSEMBLY RH
OK -- Continue to next step.

2. PERFORM SENSITIVITY CHECK

(a) Using Techstream, perform "sensitivity check" Programming and Relearning.

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.

3. CHECK DTC

(a) Turn the power switch on (IG).

(b) Clear the DTCs stored in the occupant classification ECU Reading and Clearing Diagnostic Trouble Codes.

(c) Clear the DTCs stored in the center airbag sensor assembly DTC Check / Clear.

(d) Turn the power switch off.

(e) Turn the power switch on (IG).

(f) 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 -- END
NG -- Continue to next step.

4. REPLACE FRONT SEAT WITH ADJUSTER FRAME ASSEMBLY RH

(a) Turn the power switch off.

(b) Disconnect the negative (-) terminal cable from the battery.

(c) Replace the front seat with adjuster frame assembly RH Removal for power seat or Removal for manual seat).

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 Techstream to the DLC3.

(c) Turn the power switch on (IG).

(d) Using Techstream, perform "zero point calibration" Programming and Relearning.

OK:

"Zero Point Calibration is complete." is displayed.

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

6. PERFORM SENSITIVITY CHECK

(a) Using Techstream, perform "sensitivity check" Programming and Relearning.

Standard value:

27 to 33 kg (59.52 to 72.75 lb)

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

7. CHECK DTC

(a) Turn the power switch on (IG).

(b) Clear the DTCs stored in the occupant classification ECU Reading and Clearing Diagnostic Trouble Codes.

(c) Clear the DTCs stored in the center airbag sensor assembly DTC Check / Clear.

(d) Turn the power switch off.

(e) Turn the power switch on (IG).

(f) 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 -- END
NG -- Continue to next step.

8. REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the power switch off.

(b) Disconnect the negative (-) terminal cable from the battery.

(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 Techstream to the DLC3.

(c) Turn the power 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.

10. PERFORM SENSITIVITY CHECK

(a) Using Techstream, perform "sensitivity check" Programming and Relearning.

Standard value:

27 to 33 kg (59.52 to 72.75 lb)

NEXT -- END