Toyota Tundra. Manual — part 464

DTC B1273 SLIDING ROOF ECU COMMUNICATION STOP

DESCRIPTION

This DTC is output when the LIN communication between the sliding roof drive gear and main body ECU stops
for 10 seconds or more.

DTC B1273 SLIDING ROOF ECU COMMUNICATION STOP DETECTION CONDITION CHART

Fig. 9: Sliding Roof ECU Communication - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

WIRING DIAGRAM

INSPECTION PROCEDURE

Connect the Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until
communication between the tester and vehicle begins.

DTC

Code

DTC Detection Condition

Trouble Area

B1273

No communication between sliding roof drive gear and main
body ECU for 10 seconds or more



Sliding roof drive gear
sub-assembly



Main body ECU



Harness or connector

NOTE:

When using the Techstream with the ignition switch OFF to troubleshoot:

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Multiplex Communication - Tundra

HINT:

DTC B2325 is also output when the communication between the sliding roof drive gear and main body ECU
stops.

1. CLEAR DTC

a. Clear the DTC (see DTC CHECK / CLEAR ).

2. CHECK FOR DTC

a. Check for DTC (see DTC CHECK / CLEAR ).

Result:

DTC B1273 SLIDING ROOF ECU COMMUNICATION STOP RESULT CHART

B: USE SIMULATION METHOD TO CHECK (See HOW TO PROCEED WITH
TROUBLESHOOTING )

A: Go to Next Step

3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF DRIVE GEAR)

Fig. 10: Identifying J2 ECU Connector And W3 Gear Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Result

Proceed to

DTC B1273 output reoccurs

A

DTC B1273 output does not reoccur

B

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Multiplex Communication - Tundra

a. Disconnect the J2 ECU connector.

b. Disconnect the W3 gear connector.

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

Standard resistance

HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF DRIVE GEAR)
RESISTANCE SPECIFICATION

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

4. CHECK HARNESS AND CONNECTOR (SLIDING ROOF DRIVE GEAR - BATTERY AND

BODY GROUND)

Fig. 11: Identifying W3 Gear Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

a. Disconnect the W3 gear connector.

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

Standard resistance

HARNESS AND CONNECTOR (SLIDING ROOF DRIVE GEAR - BATTERY AND BODY
GROUND) RESISTANCE SPECIFICATION

Standard voltage

HARNESS AND CONNECTOR (SLIDING ROOF DRIVE GEAR - BATTERY AND BODY

Tester Connection

Condition Specified Condition

J2-10 (LIN2) - W3-3 (SPD)

Always

Below 1 ohms

J2-10 (LIN2) or W3-3 (SPD) - Body ground Always

10 kohms or higher

Tester Connection

Condition Specified Condition

W3-8 (E) - Body ground Always

Below 1 ohms

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Multiplex Communication - Tundra

GROUND) VOLTAGE SPECIFICATION

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

5. REMOVE SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY

a. Temporarily replace the sliding roof drive gear with a new or normally functioning one (see

DISASSEMBLY ).

b. Clear the DTC (see DTC CHECK / CLEAR ).

6. CHECK FOR DTC

a. Check for DTC (see DTC CHECK / CLEAR ).

Result:

HARNESS AND CONNECTOR (SLIDING ROOF DRIVE GEAR - BATTERY AND BODY
GROUND) RESULT CHART

B: REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK)

A: Go to Next Step

END (SLIDING ROOF DRIVE GEAR IS DEFECTIVE)

DTC B2325 LIN COMMUNICATION BUS MALFUNCTION

DESCRIPTION

The main body ECU intermittently monitors the LIN communication bus between the components related to the
door and sliding roof. DTC B2325 is output when a malfunction in the LIN communication bus between the
components related to sliding roof is detected consecutively 3 times.

DTC B2325 LIN COMMUNICATION BUS MALFUNCTION DETECTION CONDITION CHART

Tester Connection

Condition Specified Condition

W3-10 (B) - Body ground Always

11 to 14 V

Result

Proceed to

DTC B1273 output reoccurs

B

DTC B1273 output does not reoccur

A

DTC

Code

DTC Detection Condition

Trouble Area

B2325

Main body ECU detects malfunction of LIN communication bus
between components related to sliding roof consecutively 3 times



Sliding roof drive
gear sub-assembly



Main body ECU



Harness or connector

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Multiplex Communication - Tundra