Toyota Tundra. Manual — part 2644

OK: Go to next step

4. CHECK HARNESS AND CONNECTOR (SOURCE VOLTAGE)

a. Turn the ignition switch OFF.

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

c. Disconnect the Y2*1 or Q11*2 ECU connector.

HINT:

*1: for Power Seat

*2: for Manual Seat

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

Fig. 226: Identifying Occupant Classification ECU Connector Terminals
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

Standard voltage:

Tester Connection

Condition Specified Condition

Y2-3 (GND) - Body ground Always

Below 1 ohms

Tester Connection

Condition Specified Condition

Q11-3 (GND) - Body ground 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 HARNESS OR CONNECTOR

OK: Go to next step

5. CHECK FOR DTC

a. Turn the ignition switch OFF.

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

c. Connect the connectors to the occupant classification ECU.

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 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.

g. Turn the ignition switch OFF, and wait for at least 10 seconds.

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

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

CHECK/CLEAR ).

OK: DTC B1794 is not output.

HINT:

DTCs other than DTC B1794 may be output at this time, but they are not related to this check.

Tester Connection

Switch Condition Specified Condition

Y2-1 (+B) - Body ground

Ignition switch ON

11 to 14 V

Y2-7 (IG) - Body ground

Tester Connection

Switch Condition Specified Condition

Q11-1 (+B) - Body ground

Ignition switch ON

11 to 14 V

Q11-7 (IG) - Body ground

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

NG: Go to step 6

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

6. 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 Manual Seat (see FRONT SEAT ASSEMBLY (FOR MANUAL SEAT) )



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

HINT:

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

7. 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 ).

8. 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 B1795: OCCUPANT CLASSIFICATION ECU MALFUNCTION

DESCRIPTION

DTC B1795 is set when a malfunction is detected in the occupant classification ECU.

Troubleshoot DTC B1771 first when both DTCs B1771 and B1795 are present.

DTC TROUBLE DETECTION CONDITION TABLE

HINT:



When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform

DTC Code

DTC Detection Condition

Trouble Area

B1795

Occupant classification ECU malfunction

Occupant classification ECU

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

troubleshooting for DTC B1795 of the occupant classification system.



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

INSPECTION PROCEDURE

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, and wait for at least 10 seconds.

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 B1795 is not output.

HINT:

DTCs other than DTC B1795 may be output at this time, but they are not related to this check.

NG: Go to step 2

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

2. 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:

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

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra