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:
Dtc Check / Clear
DTC CHECK / CLEAR
1. CHECK DTC
(a) Check the DTCs.
(1) Turn the ignition switch off.
(2) Connect the Techstream to the DLC3.
(3) Turn the ignition switch to ON.
(4) Turn the Techstream on.
(5) Read the DTCs following the prompts on the Techstream screen. Enter the following
menus: Powertrai ...
Precaution
PRECAUTION
1. EXPRESSIONS OF IGNITION SWITCH
HINT:
The type of ignition switch used on this model differs according to the specifications
of the vehicle. The expressions listed in the table below are used in this section.
Expression
Ignition Switch
(Position)
...
System Description
SYSTEM DESCRIPTION
1. FRONT SEAT HEATER
(a) By operating the seat heater switch on the air conditioning control assembly,
the temperature can be controlled within the range of 36 to 42.2°C (96 to 108°F).
(b) The on/off status and heater level of each seat heater are indicated by the
respect ...
