Toyota Tundra. Manual — part 267

stops between an ECU and the main body ECU for 10 seconds or more, the ECU disappears
from the Techstream display.



For communication stop mode of ECUs connected to the CAN MS bus circuit, refer to the
DTC flowchart of the respective communication stop.

B: GO TO DTC U1002 FLOWCHART (See DTC U1002: LOST COMMUNICATION WITH
GATEWAY MODULE )

C: GO TO MAIN BODY ECU COMMUNICATION STOP MODE FLOWCHART (See MAIN
BODY ECU COMMUNICATION STOP MODE )

D: GO TO PROBLEM SYMPTOMS TABLE (See PROBLEM SYMPTOMS TABLE )

E: GO TO OPEN IN ONE SIDE OF CAN BRANCH WIRE FLOWCHART (See OPEN IN ONE
SIDE OF CAN BRANCH LINE )

A: Go to Next Step

9. CHECK COMMUNICATION MALFUNCTION DTC (PAST DTC CHECK)*

a. Select "CAN Bus Check" from the "System Select".

b. Write down all of the DTCs stored in each ECU.

HINT:



If there are communication malfunction DTCs stored but the intelligent tester's or
Techstream's "CAN Bus Check - Communication Bus Check" screen displays all of the
ECUs and sensors connected to the CAN system, the communication malfunction DTCs may
be past malfunctions that are no longer present.



For V bus main wire malfunctions, related ECUs are also detected. Therefore, determine the
malfunctioning area based on all of the DTCs that are output.



For MS bus malfunctions, DTCs are output based on the detection of communication stop
malfunctions and network malfunctions of ECUs that are connected by the main body ECU.

INSPECTION RESULT REFERENCE TABLE

B: GO TO DTC U1002 FLOW CHART (See DTC U1002: LOST COMMUNICATION WITH
GATEWAY MODULE )

Inspection Result

Proceed

to

ECU connected to V bus main wire has stored communication malfunction code (V bus
main wire past malfunction).

A

Main body ECU outputs MS bus malfunction code (U1002) (MS bus past malfunction).

B

Main body ECU outputs malfunction code other than MS bus malfunction code
(U1002) (past malfunction of ECU branch wire connected to MS bus).

C

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

C: GO TO PROBLEM SYMPTOMS TABLE (See PROBLEM SYMPTOMS TABLE )

A: Go to Next Step

10. CHECK DTC COMBINATION TABLE (V BUS CIRCUIT BRANCH WIRE OPEN PAST

MALFUNCTION)

a. Based on the combination of stored CAN communication system DTCs, determine which ECUs

and sensors have a communication stop malfunction (see DIAGNOSIS SYSTEM ).

11. PERFORM MALFUNCTION SIMULATION TEST (V BUS CIRCUIT MAIN WIRE PAST

MALFUNCTION)*

a. Using the Techstream, clear all DTCs.

b. Perform a malfunction simulation test on all harnesses and connectors related to the V bus circuit

main wire.

c. Check the DTCs that were output as a result of the malfunction simulation test. Then determine the

malfunctioning area.

12. ADJUST, REPAIR AND REPLACE

13. CONFIRMATION TEST

NEXT: END

PROBLEM SYMPTOMS TABLE

HINT:



Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are
listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area"
column of the table. Check each symptom by checking the suspected areas in the order they are listed.
Replace parts as necessary.



Inspect the fuses and relays related to this system before inspecting the suspected areas below.

RESULT LIST OF CHECK CAN BUS LINE

PROBLEM SYMPTOMS TABLE

Symptom

Suspected Area

Reference

The result of "HOW TO PROCEED
WITH TROUBLESHOOTING" is
"Open in CAN Main Wire"

OPEN IN CAN MAIN WIRE

OPEN IN CAN MAIN WIRE

The result of "HOW TO PROCEED
WITH TROUBLESHOOTING" is
"Short in CAN Bus Lines"

SHORT IN CAN BUS LINES

SHORT IN CAN BUS LINES

The result of "HOW TO PROCEED
WITH TROUBLESHOOTING" is
"Short to +B in CAN Bus Line"

SHORT TO B+ IN CAN BUS
LINE

SHORT TO B+ IN CAN BUS

LINE

The result of "HOW TO PROCEED
WITH TROUBLESHOOTING" is

SHORT TO GND IN CAN
BUS LINE

SHORT TO GND IN CAN

BUS LINE

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

COMMUNICATION STOP MODE TABLE

PROBLEM SYMPTOMS TABLE

TERMINALS OF ECU

HINT:

"Short to GND in CAN Bus Line"
The result of "HOW TO PROCEED
WITH TROUBLESHOOTING" is
"Open in One Side of CAN Branch
Line"

OPEN IN ONE SIDE OF CAN
BRANCH LINE

OPEN IN ONE SIDE OF

CAN BRANCH LINE

Symptom

Suspected Area

Reference

ABS/VSC/TRAC not displayed
on Techstream

SKID CONTROL ECU
COMMUNICATION STOP
MODE

SKID CONTROL ECU

COMMUNICATION STOP

MODE

Air Conditioner not displayed on
Techstream

AIR CONDITIONING
AMPLIFIER
COMMUNICATION STOP
MODE

AIR CONDITIONING

AMPLIFIER

COMMUNICATION STOP

MODE

Engine not displayed on
Techstream

ECM COMMUNICATION STOP
MODE

ECM COMMUNICATION STOP

MODE

Main Body not displayed on
Techstream

MAIN BODY ECU
COMMUNICATION STOP
MODE

MAIN BODY ECU

COMMUNICATION STOP

MODE

Combination Meter not
displayed on Techstream

COMBINATION METER ECU
COMMUNICATION STOP

COMBINATION METER ECU

COMMUNICATION STOP

MODE

SRS Airbag not displayed on
Techstream

AIRBAG ECU
COMMUNICATION STOP
MODE

CENTER AIRBAG SENSOR

COMMUNICATION STOP

MODE

Steering Angle Sensor not
displayed on Techstream

STEERING ANGLE SENSOR
COMMUNICATION STOP
MODE

STEERING ANGLE SENSOR

COMMUNICATION STOP

MODE

Four Wheel Drive Control not
displayed on Techstream*1

4WD CONTROL ECU
COMMUNICATION STOP
MODE

4WD CONTROL ECU

COMMUNICATION STOP

MODE

Accessory Gateway not
displayed on Techstream*2

BUS BUFFER ECU
COMMUNICATION STOP
MODE

BUS BUFFER ECU

COMMUNICATION STOP

MODE

HINT:



*1: w/ 4WD



*2: w/ Bus Buffer ECU

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

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. JUNCTION CONNECTOR

a. NO. 1 JUNCTION CONNECTOR

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

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

NOTE:



Before measuring the resistance, leave the vehicle for at least 1
minute and do not operate the ignition switch, any switches or
doors. If doors need to be opened in order to check connectors,
open the doors and leave them open.



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 ACCESSORIES & EQUIPMENT CAN Communication - Tundra