Toyota Tundra. Manual — part 285

Fig. 66: Identifying ECM Communication Stop Mode - Wiring Diagram (2 Of 2)
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. CHECK HARNESS AND CONNECTOR (ECM - BATTERY AND BODY GROUND)

a. Disconnect the A24 and D74 ECM connectors.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION TABLE

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

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

Standard voltage

STANDARD VOLTAGE SPECIFICATION TABLE

Fig. 67: Identifying A24 And D74 ECM Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Tester Connection

Condition Specified Condition

D74-81 (E1) - Body ground

Always

Below 1 ohms

D74-42 (E02) - Body ground
D74-43 (E01) - Body ground

D74-82 (ME01) - Body ground

Tester Connection

Condition

Specified

Condition

A24-1 (BATT) - Body

ground

Always

11 to 14 V

A24-2 (+B2) - Body

ground

When battery's positive (+) voltage is applied to
terminal MREL

A24-3 (+B) - Body ground

When battery's positive (+) voltage is applied to
terminal MREL

A24-34 (MREL) - Body

ground

Ignition switch OFF

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

Result

RESULT REFERENCE TABLE

B: REPLACE ECM (See REMOVAL )

C: REPLACE ECM (See REMOVAL )

D: REPAIR OR REPLACE HARNESS OR CONNECTOR

A: REPLACE ECM (See REMOVAL )

MAIN BODY ECU COMMUNICATION STOP MODE

DESCRIPTION

SYMPTOM TABLE

WIRING DIAGRAM

Result

Proceed to

OK (for 1GR-FE)

A

OK (for 2UZ-FE)

B

OK (for 3UR-FE)

C

NG

D

Detection Item

Symptom

Trouble Area

MAIN BODY ECU
COMMUNICATION STOP
MODE

When either condition below is met:



Main Body is not displayed on "CAN Bus
Check".



Applies to "MAIN BODY ECU
COMMUNICATION STOP MODE" in
"DTC COMBINATION TABLE".



Power source or
inside main body
ECU



Main body ECU
branch wire or
connector (V Bus)



Main body ECU

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

Fig. 68: Identifying Main Body 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.

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

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra