Toyota Tundra. Manual — part 2632

DTCs other than DTC B1782 may be output at this time, but they are not related to this check.

NG: Go to step 10

OK: END

10. REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH

a. Turn the ignition switch OFF.

b. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

c. Replace the front seat frame with adjuster RH (see FRONT POWER SEAT MOTOR

ASSEMBLY (FOR POWER SEAT) ).

HINT:

Perform the inspection using parts from a normal vehicle when possible.

11. PERFORM ZERO POINT CALIBRATION

a. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

b. Connect the Techstream to the DLC3.

c. Turn the ignition switch ON, and wait for at least 60 seconds.

d. Using the Techstream, perform the zero point calibration (see INITIALIZATION ).

12. PERFORM SENSITIVITY CHECK

a. Using the Techstream, perform the sensitivity check (see INITIALIZATION ).

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

NEXT: END

DTC B1783: REAR OCCUPANT CLASSIFICATION SENSOR RH CIRCUIT MALFUNCTION

DESCRIPTION

The rear occupant detection sensor RH circuit consists of the occupant classification ECU and the rear occupant
detection sensor RH.

DTC B1783 is set when a malfunction is detected in the rear occupant detection sensor RH circuit.

DTC TROUBLE DETECTION CONDITION TABLE

DTC

Code

DTC Detection Condition

Trouble Area

One of following conditions is met:



Occupant classification ECU receives line short circuit



Front seat frame with
adjuster RH (Rear

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

HINT:



When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform
troubleshooting for DTC B1783 of the occupant classification system.



Use the Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be
read.

WIRING DIAGRAM

Fig. 213: Identifying Rear Occupant Classification Sensor RH Circuit Malfunction Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

B1783

signal, open circuit signal, short circuit to ground signal
or short circuit to +B signal in rear occupant detection
sensor RH circuit for 2 seconds



Rear occupant detection sensor RH malfunction



Occupant classification ECU malfunction

occupant detection sensor
RH)



Front seat wire RH



Occupant classification
ECU

NOTE:

After the ignition switch is turned OFF, the navigation system requires
approximately 90 seconds to record various types of memory and settings. As a
result, after turning the ignition switch OFF, wait 90 seconds or more before

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

HINT:



If troubleshooting (wire harness inspection) is difficult to perform, remove the front seat RH installation
bolts to see the undersurface of the seat cushion.



In the above case, hold the seat so that it does not fall down. Holding the seat for a long period of time
may cause problems, such as seat rail deformation. Hold the seat up only for as long as necessary.

1. CHECK FOR DTC

a. Turn the ignition switch ON, and wait for at least 60 seconds.

b. Clear any DTCs stored in the memory (see DTC CHECK/CLEAR ).

HINT:



First clear DTCs stored in the occupant classification ECU and then in the center airbag
sensor.



Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the
DTCs cannot be cleared.

c. Turn the ignition switch OFF.

d. Turn the ignition switch ON, and wait for at least 60 seconds.

e. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC

CHECK/CLEAR ).

OK: DTC B1783 is not output.

HINT:

DTCs other than DTC B1783 may be output at this time, but they are not related to this check.

NG: Go to step 22

OK: USE SIMULATION METHOD TO CHECK (See DIAGNOSIS SYSTEM )

2. CHECK CONNECTION OF CONNECTOR

a. Turn the ignition switch OFF.

b. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

c. Check that the connectors are properly connected to the occupant classification ECU and the rear

occupant detection sensor RH.

OK: Connectors are properly connected.

NG: CONNECT CONNECTOR

disconnecting the cable from the negative (-) battery terminal.

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

OK: Go to next step

3. CHECK CONNECTOR

a. Check that the connectors (on the occupant classification ECU side and rear occupant detection

sensor RH side) are not damaged (see ELECTRONIC CIRCUIT INSPECTION
PROCEDURE ).

OK: Connectors are not deformed or damaged.

NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

4. CHECK FRONT SEAT WIRE RH

a. Disconnect the connectors from the occupant classification ECU and the rear occupant detection

sensor RH.

b. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

c. Turn the ignition switch ON, and wait for at least 60 seconds.

d. Measure the voltage according to the value(s) in the table below.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

e. Turn the ignition switch OFF.

f. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

g. Using service wires, connect terminals 1 (SVC4) and 3 (SGD4), and connect terminals 2 (SIG4)

and 3 (SGD4) of connector C.

h. Measure the resistance according to the value(s) in the table below.

Tester Connection

Switch Condition Specified Condition

Y1-4 (SGD4) - Body ground

Ignition switch ON

Below 1 V

Y1-6 (SVC4) - Body ground

Y1-10 (SIG4) - Body ground

NOTE:

Do not forcibly insert the service wires into the terminals of the
connector.

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra