Toyota Tacoma (2015-2018) Service Manual: Rear Occupant Classification Sensor LH Collision Detection (B1787)
DESCRIPTION
DTC B1787 is set when the occupant detection ECU receives a collision detection signal, which is sent by the occupant classification sensor rear LH when an accident occurs.
DTC B1787 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 detection ECU outputs a collision detection signal, even if the vehicle is not 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 No. |
DTC Detecting Conditions |
Trouble Areas |
|---|---|---|
|
B1787 |
|
|
HINT:
- When DTC B1650/32 is set as a result of troubleshooting the supplemental restraint system, perform troubleshooting for DTC B1787 of the occupant classification system.
- Use the Techstream to check for DTCs of the occupant detection ECU, otherwise the DTCs cannot be read.
WIRING DIAGRAM
(See page .gif)
)
PROCEDURE
|
1. |
CHECK DTC |
(a) Turn the ignition switch to the ON position.
(b) Clear any DTCs stored in the airbag sensor assembly (See page
).
(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 detection ECU (See page
).
OK:
DTC B1787 is not output.
HINT:
DTCs other than B1787 may be output at this time, but they are not related to this check.
| OK | .gif) |
USE SIMULATION METHOD TO CHECK |
|
.gif)
|
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 (See page
).
OK:
"Zero Point Calibration is complete." is displayed on the Techstream.
| NG | |
GO TO STEP 5 |
|
|
3. |
PERFORM SENSITIVITY CHECK |
(a) Using the Techstream, perform the sensitivity check (See page
).
Standard :
27 to 33 kg (59.52 to 72.75 lb)
| NG | |
GO TO STEP 5 |
|
|
4. |
CHECK DTC |
(a) Turn the ignition switch to the ON position.
(b) Clear any DTCs stored in the airbag sensor assembly (See page
).
(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 detection ECU (See page
).
OK:
DTC B1787 is not output.
HINT:
DTCs other than B1787 may be output at this time, but they are not related to this check.
| OK | |
USE SIMULATION METHOD TO CHECK |
|
|
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 (See page
).
HINT:
Perform the inspection using parts from a normal vehicle when possible.
|
|
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 (See page
).
OK:
"Zero Point Calibration is complete." is displayed on the Techstream.
| NG | |
GO TO STEP 9 |
|
|
7. |
PERFORM SENSITIVITY CHECK |
(a) Using the Techstream, perform the sensitivity check (See page
).
Standard:
27 to 33 kg (59.52 to 72.75 lb)
| NG | |
GO TO STEP 9 |
|
|
8. |
CHECK DTC |
(a) Connect the connectors to the occupant detection ECU and the rear 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 (See page
).
HINT:
- First clear DTCs stored in the occupant detection ECU and then in the airbag sensor assembly.
- Use the Techstream to clear the DTCs of the occupant detection 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 detection ECU (See page
).
OK:
DTC B1787 is not output.
HINT:
DTCs other than B1787 may be output at this time, but they are not related to this check.
| OK | |
USE SIMULATION METHOD TO CHECK |
|
|
9. |
REPLACE OCCUPANT DETECTION 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 detection ECU (See page
).
|
|
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 (See page
1).
OK:
"Zero Point Calibration is complete." is displayed on the Techstream.
|
|
11. |
PERFORM SENSITIVITY CHECK |
(a) Using the Techstream, perform the sensitivity check (See page
).
Standard:
27 to 33 kg (59.52 to 72.75 lb)
| NEXT | |
USE SIMULATION METHOD TO CHECK |
Occupant Classification ECU Malfunction (B1795)
DESCRIPTION
DTC B1795 is set when a malfunction is detected in the occupant detection ECU.
Troubleshoot DTC B1771 first when both DTCs B1771 and B1795 are present.
DTC No.
DTC ...
Rear Occupant Classification Sensor RH Collision Detection (B1788)
DESCRIPTION
DTC B1788 is set when the occupant detection ECU receives a collision detection
signal, which is sent by the occupant classification sensor rear RH when an accident
occurs.
DTC B1788 ...
Other materials:
Theft Deterrent System Presence Detection (B279C,B279C95)
DESCRIPTION
If an ECM that is incompatible with the engine immobiliser system is installed,
the ECM stores this DTC.
DTC No.
DTC Detection Condition
Trouble Area
DTC Output Confirmation Operation
B279C*1
An ECM that is incom ...
Purge Valve
Components
COMPONENTS
ILLUSTRATION
Inspection
INSPECTION
PROCEDURE
1. INSPECT PURGE VSV
(a) Measure the resistance according to the value(s) in the table below.
Text in Illustration
*a
Component without harness connected
(Purge VSV ...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
If a trouble code is displayed during the DTC check, check the circuit listed
for the code in the table below (proceed to the page listed for that circuit).
1. Occupant Detection ECU
HINT:
When DTC B1650/32 is detected as a result of troubleshooting the Supplement ...
