DESCRIPTION
DTC B1787 is stored when the occupant classification ECU receives a collision detection signal, which is sent by the rear occupant classification sensor LH when an accident occurs.
DTC B1787 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 B1787 can be cleared by conducting the zero point calibration and sensitivity check.
Therefore, if DTC B1787 is output, first perform the zero point calibration and sensitivity check.
DTC Code |
DTC Detection Condition |
Trouble Area |
---|---|---|
B1787 |
Either condition is met:
|
|
HINT:
WIRING DIAGRAM
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 the center airbag sensor (See page
).
(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 (See
page ).
OK:
DTC B1787 is not output.
HINT:
DTCs other than DTC B1787 may be output at this time, but they are not related to this check.
OK | ![]() |
USE SIMULATION METHOD TO CHECK |
|
2. |
PERFORM ZERO POINT CALIBRATION |
(a) Using the Techstream, perform the zero point calibration (See page
).
OK:
"Zero Point Calibration is complete." is displayed.
NG | ![]() |
GO TO STEP 5 |
|
3. |
PERFORM SENSITIVITY CHECK |
(a) Using the Techstream, perform the sensitivity check (See page
).
Standard range:
27 to 33 kg (59.5 to 72.8 lb)
NG | ![]() |
GO TO STEP 5 |
|
4. |
CHECK FOR DTC |
(a) Clear the DTCs stored in the center airbag sensor (See page
).
(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 (See
page ).
OK:
DTC B1787 is not output.
HINT:
DTCs other than DTC B1787 may be output at this time, but they are not related to this check.
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) for Manual Seat:
(1) Replace the separate type front seat cushion spring RH (See page
).
(d) for Power Seat:
(1) Replace the separate type front seat cushion spring RH (See page
).
HINT:
Perform the inspection using parts from a normal vehicle when possible.
|
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, and wait for at least 60 seconds.
(c) Using the Techstream, perform the zero point calibration (See page
).
OK:
"Zero Point Calibration is complete." is displayed.
NG | ![]() |
GO TO STEP 9 |
|
7. |
PERFORM SENSITIVITY CHECK |
(a) Using the Techstream, perform the sensitivity check (See page
).
Standard range:
27 to 33 kg (59.5 to 72.8 lb)
NG | ![]() |
GO TO STEP 9 |
|
8. |
CHECK FOR DTC |
(a) Clear the DTCs stored in memory (See page ).
HINT:
(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 (See
page ).
OK:
DTC B1787 is not output.
HINT:
DTCs other than DTC B1787 may be output at this time, but they are not related to this check.
OK | ![]() |
END |
|
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 (See page
).
HINT:
Perform the inspection using parts from a normal vehicle when possible.
|
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, and wait for at least 60 seconds.
(c) Using the Techstream, perform the zero point calibration (See page
).
OK:
"Zero Point Calibration is complete." is displayed.
|
11. |
PERFORM SENSITIVITY CHECK |
(a) Using the Techstream, perform the sensitivity check (See page
).
Standard range:
27 to 33 kg (59.5 to 72.8 lb)
NEXT | ![]() |
END |
Disposal
DISPOSAL
CAUTION / NOTICE / HINT
HINT:
When scrapping vehicles equipped with a seat belt pretensioner or disposing of
a front seat outer belt (with seat belt pretensioner), always activate the seat
belt pretensioner first in accordance with the procedur ...
Maintenance requirements
To ensure safe and economical driving, day-to-day care and regular
maintenance are essential. It is the owner’s responsibility to perform regular
checks. Toyota recommends performing the following maintenance:
General maintenance
General mainten ...