Toyota Tacoma (2015-2018) Service Manual: Sleep Operation Failure of Occupant Classification ECU (B1796)
DESCRIPTION
During sleep mode, the occupant detection ECU monitors the condition of each sensor while the ignition switch is off. In this mode, if the occupant detection ECU detects an internal malfunction, DTC B1796 is set.
|
DTC No. |
DTC Detections Conditions |
Trouble Areas |
|---|---|---|
|
B1796 |
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 B1796 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 B1796 is not output.
HINT:
DTCs other than B1796 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 |
Terminals Of Ecu
TERMINALS OF ECU
1. OCCUPANT DETECTION ECU
Symbols (Terminal No.)
Wiring Color
Terminal Description
Condition
Specification
...
Data List / Active Test
DATA LIST / ACTIVE TEST
HINT:
By accessing the Data List displayed by the Techstream, you can check values
of switches and sensors without removing any parts. Reading the Data List as the
first ...
Other materials:
Rear Door Courtesy Switch
Inspection
INSPECTION
PROCEDURE
1. INSPECT REAR DOOR COURTESY SWITCH
(a) Check the resistance.
(1) Measure the resistance using an ohmmeter, and check the results in accordance
with the value( s) in the table below.
Standard:
Tester Connection
Condition
S ...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
TOUCH SELECT 2-4 AND HIGH-LOW SYSTEM
DTC Code
Detection Item
See page
P163B
4WD ECU Malfunction
P17A0
Automatic Disconnecting Differential Motor Control Circuit Open
...
Removal
REMOVAL
PROCEDURE
1. REMOVE FRONT DOOR SCUFF PLATE LH (for Double Cab)
2. REMOVE FRONT DOOR SCUFF PLATE LH (for Access Cab)
3. REMOVE COWL SIDE TRIM BOARD LH
4. REMOVE INSTRUMENT CLUSTER CENTER FINISH PANEL SUB-ASSEMBLY
5. REMOVE INSTRUMENT CLUSTER FINISH PANEL ASSEMBLY
6. ...
