Toyota Tundra. Manual — part 288

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION TABLE

Fig. 77: Identifying A25 4WD Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE 4WD CONTROL ECU BRANCH WIRE OR CONNECTOR
(CANH, CANL)

OK: Go to Next Step

3. CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - BATTERY AND BODY

GROUND)

a. Reconnect the cable to the negative (-) battery terminal before measuring the resistances of the

main wire and the branch wire.

b. Disconnect the A26 4WD control ECU connector.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION TABLE

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

Tester Connection

Switch Condition Specified Condition

A25-19 (CANH) - A25-20 (CANL) Ignition switch OFF

54 to 69 ohms

Tester Connection

Condition Specified Condition

A26-4 (GND) - Body ground Always

Below 1 ohms

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

Standard voltage

STANDARD VOLTAGE SPECIFICATION TABLE

Fig. 78: Identifying A26 4WD Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE 4WD CONTROL ECU (See REMOVAL )

BUS BUFFER ECU COMMUNICATION STOP MODE

DESCRIPTION

SYMPTOM TABLE

WIRING DIAGRAM

Tester Connection

Switch Condition Specified Condition

A26-3 (IG) - Body ground Ignition switch ON

11 to 14 V

Detection Item

Symptom

Trouble Area

BUS BUFFER ECU
COMMUNICATION STOP
MODE

When either condition below is met:



Accessory Gateway is not displayed on
"CAN Bus Check".



Applies to "BUS BUFFER ECU
COMMUNICATION STOP MODE" in
"DTC COMBINATION TABLE".



Bus buffer ECU
branch wire or
connector



Bus buffer ECU

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

Fig. 79: Identifying Bus Buffer ECU Communication Stop Mode Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

HINT:

Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with
the CAN, which causes resistance variation.

1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

a. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the

main wire and the branch wire.

2. CHECK FOR OPEN IN CAN BUS WIRE (BUS BUFFER ECU BRANCH WIRE)

a. Disconnect the J59 bus buffer ECU connector.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION TABLE

CAUTION: Wait at least 90 seconds after disconnecting the cable from the

negative (-) battery terminal to prevent airbag and seat belt
pretensioner activation.

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.

Tester Connection

Switch Condition Specified Condition

J59-3 (CAN+) - J59-2 (CAN-) Ignition switch OFF

54 to 69 ohms

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

Fig. 80: Identifying J59 Bus Buffer ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE BUS BUFFER ECU BRANCH WIRE OR CONNECTOR (CAN+,
CAN-)

OK: REPLACE BUS BUFFER ECU

OPEN IN CAN MAIN WIRE

DESCRIPTION

There may be an open circuit in the CAN main wire and/or the DLC3 branch wire when the resistance between
terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 ohms or higher.

SYMPTOM TABLE

WIRING DIAGRAM

Symptom

Trouble Area

Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is
69 ohms or higher.



CAN main wire and
connector



No. 1 junction connector



No. 2 junction connector



ECM



Combination Meter ECU

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra