Toyota Tundra. Manual — part 2626

Fig. 206: Identifying Front Seat Wire RH
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Standard Resistance:

for Power Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

for Manual Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

h. Disconnect the service wire from connector C.

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

Standard Resistance:

Tester Connection

Condition Specified Condition

Y2-9 (BSW) - Y2-5 (BGND) Always

Below 1 ohms

Tester Connection

Condition Specified Condition

Q11-9 (BSW) - Q11-5 (BGND) Always

Below 1 ohms

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

for Power Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

for Manual Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

5. CHECK FOR DTC

a. Connect the connectors to the occupant classification ECU and the front seat inner belt 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. Clear the 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.

e. Turn the ignition switch OFF.

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

g. Check for DTCs (see DTC CHECK/CLEAR ).

OK: DTC B1771 is not output.

HINT:

Codes other than DTC B1771 may be output at this time, but they are not related to this check.

NG: Go to step 6

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

Tester Connection

Condition Specified Condition

Y2-9 (BSW) - Body ground

Always

1 Mohms or higher

Y2-5 (BGND) - Body ground

Y2-9 (BSW) - Y2-5 (BGND)

Tester Connection

Condition Specified Condition

Q11-9 (BSW) - Body ground

Always

1 Mohms or higher

Q11-5 (BGND) - Body ground

Q11-9 (BSW) - Q11-5 (BGND)

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

6. REPLACE FRONT SEAT INNER BELT 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 inner belt RH (see FRONT SEAT INNER BELT ASSEMBLY ).

HINT:

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

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

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

f. Clear the 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.

g. Turn the ignition switch OFF.

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

i. Check for DTCs (see DTC CHECK/CLEAR ).

OK: DTC B1771 is not output.

HINT:

Codes other than DTC B1771 may be output at this time, but they are not related to this check.

NG: Go to step 7

OK: END

7. REPLACE OCCUPANT CLASSIFICATION ECU

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 occupant classification ECU.



for Power Seat (see FRONT SEAT ASSEMBLY (FOR POWER SEAT) )



for Manual Seat (see FRONT SEAT ASSEMBLY (FOR FOLD DOWN SEAT TYPE) )

HINT:

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

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

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

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

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

HINT:

If the DTCs are not cleared at this time, past DTCs will remain.

8. PERFORM ZERO POINT CALIBRATION

a. Connect the Techstream to the DLC3.

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

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

9. 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 B1780: FRONT OCCUPANT CLASSIFICATION SENSOR LH CIRCUIT MALFUNCTION

DESCRIPTION

The front occupant detection sensor LH circuit consists of the occupant classification ECU and the front
occupant detection sensor LH.

DTC B1780 is set when a malfunction is detected in the front occupant detection sensor LH circuit.

DTC TROUBLE DETECTION CONDITION TABLE

HINT:



When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform
troubleshooting for DTC B1780 of the occupant classification system.



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

DTC

Code

DTC Detection Condition

Trouble Area

B1780

One of following conditions is met:



Occupant classification ECU receives line short circuit
signal, open circuit signal, short circuit to ground signal
or short circuit to +B signal in front occupant detection
sensor LH circuit for 2 seconds



Front occupant detection sensor LH malfunction



Occupant classification ECU malfunction



Front seat frame with
adjuster RH (Front
occupant detection sensor
LH)



Front seat wire RH



Occupant classification
ECU

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra