Toyota Tacoma 2015-2018 Service Manual: 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 Detections Conditions |
Trouble Areas |
|---|---|---|
|
B1795 |
Occupant detection ECU malfunction |
Occupant detection ECU |
HINT:
- When DTC B1650/32 is detected as a result of troubleshooting the supplemental restraint system, perform troubleshooting for DTC B1795 of the occupant classification system.
- Use the Techstream to check for DTCs of the occupant detection ECU, otherwise the DTCs cannot be read.
PROCEDURE
|
1. |
CHECK DTC |
(a) Turn the ignition switch to the ON position.
(b) Clear any DTCs stored in the memory (See page
.gif)
).
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.
(c) Turn the ignition switch to the LOCK position, and wait for at least 10 seconds.
(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 B1795 is not output.
HINT:
DTCs other than B1795 may be output at this time, but they are not related to this check.
| OK | .gif) |
USE SIMULATION METHOD TO CHECK |
|
.gif)
|
2. |
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
).
HINT:
Perform the inspection using parts from a normal vehicle when possible.
|
|
3. |
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.
|
|
4. |
PERFORM SENSITIVITY CHECK |
(a) Using the Techstream, perform the sensitivity check (See page
).
Standard :
Standard value: 27 to 33 kg (59.52 to 72.75 lb)
| NEXT | |
END |
Open in Occupant Classification ECU Battery Positive Line (B1794)
DESCRIPTION
DTC B1794 is set when a malfunction is detected in the occupant detection ECU.
DTC No.
DTC Detections Conditions
Trouble Areas
B1794
...
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 ...
Other materials:
Inspection
INSPECTION
PROCEDURE
1. INSPECT BRAKE VACUUM CHECK VALVE ASSEMBLY
(a) Check that there is ventilation from the booster to the engine, and
no ventilation from the engine to the booster.
If the results are not as specified, replace the vacuum check valve.
...
Monitor Drive Pattern
MONITOR DRIVE PATTERN
1. TEST MONITOR DRIVE PATTERN FOR ECT
CAUTION:
Perform this drive pattern on a level surface and strictly observe the posted
speed limits and traffic laws while driving.
HINT:
Performing this drive pattern is one method to simulate the ECM (ECT) malfunction
detection c ...
Parts Location
PARTS LOCATION
ILLUSTRATION
*A
for Vacuum Brake Booster
*B
for Hydraulic Brake Booster
*1
BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU)
*2
BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU)
...