Control Module Communication Bus Off U0073 Toyota Vitz

HINT:

• In the CAN communication system, CAN

communication system DTCs output by the ECU can be displayed by using the intelligent tester.

• If CAN communication system DTCs are output, trouble cannot be determined solely from the DTCs. Perform troubleshooting according to "HOW TO PROCEED WITH TROUBLESHOOTING" (See page CA-9).

(a) BRAKE ACTUATOR (SKID CONTROL ECU) HINT:

DTC communication uses the CAN communication system.

DTC No.

Detection Item

U0073/94

Control Module Communication Bus OFF

(b) POWER STEERING ECU HINT:

DTC communication uses the SIL Line.

DTC No.

Detection Item

U0073

Control Module Communication Bus OFF

U0105

Lost Communication with ECM

U0121*

Lost Communication with Anti-lock Brake System (ABS) Control Module

*: For vehicle with ABS only. (c) COMBINATION METER ASSEMBLY HINT:

DTC communication uses the CAN communication system.

DTC No.

Detection Item

U0100

Lost Communication with ECM/PCM "A"

U0129*

Lost Communication with Brake System Control Module

*: For vehicle with ABS only. (d) AIR CONDITIONING AMPLIFIER HINT:

DTC communication uses the CAN communication system.

DTC No.

Detection Item

B1499/99

Multiplex Communication Circuit

(e) MAIN BODY ECU

HINT:

• The main body ECU is connected to the CAN communication system but CAN communication DTCs are not output.

• If "MAIN BODY" is not displayed on the "BUS CHECK" screen on the intelligent tester, proceed to "Main Body ECU Communication Stop Mode." (See page CA-35)

(f) CENTER AIRBAG SENSOR ASSEMBLY

HINT:

• The center airbag sensor assembly is connected to the CAN communication system but CAN communication DTCs are not output.

• If "SRS AIRBAG" is not displayed on the "BUS CHECK" screen on the intelligent tester, proceed to "Center Airbag Sensor Communication Stop Mode." (See page CA-40)

HINT:

• The ECM is connected to the CAN communication system but CAN communication DTCs are not output.

• If "ENGINE" is not displayed on the "BUS CHECK" screen on the intelligent tester, proceed to "ECM Communication Stop Mode." (See page CA-33)

4. DTC COMBINATION TABLE

DTC

Trouble Mode

Output from

Output DTC

Brake Actuator (Skid Control

ECU) Communicati on Stop Mode

Power Steering ECU Communicati on Stop Mode

ECM Communicati on Stop Mode

Center Airbag Sensor Communicati on Stop Mode

Conditioning

Amplifier Communicati on Stop Mode

Combination Meter ECU Communicati on Stop Mode

Main Body ECU Communicati on Stop Mode

Brake Actuator (Skid Control ECU)

U0073/94

0*1

X

X

X

X

X

X

Power Steering ECU

U0073

X

O

X

X

X

X

X

U0105

X

O

O

X

X

X

X

U0121

O

O

X

X

X

X

X

Combination Meter ECU

U0100

X

X

O

X

X

X

X

U0129

O

X

X

X

X

X

X

Conditioning Amplifier

B1499/99

X

X

0*2

X

X

0*2

X

No DTC

X

X

X

O

O

X

• O: It is necessary to check for the trouble mode.

• *1: The brake actuator (skid control ECU) detects U0073/94 when DTC communication fails in succession. However, this DTC may not be output when the CAN communication system malfunctions.

• *2: This DTC is output when communication failures from the ECM and the combination meter ECU occur.

(a) Perform troubleshooting according to the combination of DTCs output. HINT:

• Brake Actuator (Skid Control ECU) Communication Stop Mode: (See page CA-27)

• Power Steering ECU Communication Stop Mode: (See page CA-31)

• ECM Communication Stop Mode: (See page CA-33)

• Center Airbag Sensor Communication Stop Mode: (See page CA-40)

Air Conditioning Amplifier Communication Stop

Combination Meter ECU Communication Stop

Main Body ECU Communication Stop Mode:

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