Toyota Tacoma (2015-2018) Service Manual: 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 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 B1788 can be cleared by conducting the zero point calibration and sensitivity check.
Therefore, if DTC B1788 is output, first perform the zero point calibration and sensitivity check.
|
DTC No. |
DTC Detecting Conditions |
Trouble Areas |
|---|---|---|
|
B1788 |
|
|
HINT:
- When DTC B1650/32 is set as a result of troubleshooting the supplemental restraint system, perform troubleshooting for DTC B1788 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 B1788 is not output.
HINT:
DTCs other than B1788 may be output at this time, but they are not related to this check.
| OK | .gif) |
OTHERS 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 the 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 B1788 is not output.
HINT:
DTCs other than B1788 may be output at this time, but they are not related to this check.
| OK | |
OTHERS 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 RH.
(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 B1788 is not output.
HINT:
DTCs other than B1788 may be output at this time, but they are not related to this check.
| OK | |
OTHERS 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
).
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 | |
OTHERS USE SIMULATION METHOD TO CHECK |
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 ...
Rear Occupant Classification Sensor RH Circuit Malfunction (B1783)
DESCRIPTION
The rear occupant classification sensor RH circuit consists of the occupant detection
ECU and the rear occupant classification sensor RH.
DTC B1783 is set when a malfunction is detecte ...
Other materials:
Inspection
INSPECTION
PROCEDURE
1. INSPECT COOLER (ROOM TEMPERATURE. SENSOR) THERMISTOR
(a) Check the resistance.
(1) Measure the resistance according to the value(s) in the table below.
Text in Illustration
*a
Component without harness connected
(coo ...
Removal
REMOVAL
PROCEDURE
1. REMOVE WATER INLET WITH THERMOSTAT SUB-ASSEMBLY
(See page )
2. REMOVE NO. 1 RADIATOR HOSE
3. REMOVE NO. 2 RADIATOR HOSE
4. DISCONNECT RADIATOR RESERVE TANK HOSE
5. SEPARATE TRANSMISSION OIL COOLER HOSE (for Automatic Transmission)
(a) Disengage the c ...
Freeze Frame Data
FREEZE FRAME DATA
1. DESCRIPTION
The ECM records vehicle and driving condition information as freeze frame data
the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful
in determining whether the vehicle was moving or stationary, whether the engine
was warmed up or ...
