Can Communication System How To Proceed With Troubleshooting

Power Source Network. Corolla. Zre142 Aze141
Networking. Corolla. Zre142 Aze141

  1. CHECK AND CLEAR DTCS*

  2. CHECK CAN NO. 1 BUS WIRE

  3. CHECK TECHSTREAM

  4. RECHECK DTC

  5. DTC COMBINATION TABLE

  6. CIRCUIT INSPECTION

  7. IDENTIFICATION OF PROBLEM

  8. REPAIR OR REPLACE

  9. CONFIRMATION TEST

Can Communication System -- How To Proceed With Troubleshooting


NOTICE:
  1. DTCs for the CAN communication system are as follows: U0073, U0100*1, U0123*1, U0124*1, U0126*1, U0129, U0327*2, U1002*2 and B1499.
    *1: w/ VSC
    *2: w/ Smart key system
  2. Refer to troubleshooting of each system if DTCs regarding the CAN communication system are not output.
HINT:
*: Use the Techstream.


1.CHECK AND CLEAR DTCS*
    HINT:
    1. CAN communication DTCs are output when there is an open or short in any of the communication wires. Any problems with the power source of a corresponding ECU or sensor, or problem in the ECU or the sensor itself also cause these DTCs to be output.
    2. If a CAN communication wire connector is disconnected with the ignition switch ON, the ECUs of the corresponding system and related systems record a DTC.

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2.CHECK CAN NO. 1 BUS WIRE

  1. Check the CAN bus wire (COROLLA_ZRE142 RM000000VC801UX.html).


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3.CHECK TECHSTREAM

  1. Using the Techstream, display the "CAN Bus Check" screen (COROLLA_ZRE142 RM000000WIB0BUX.html).

  2. Observe the screen for approximately 1 minute to check the ECUs and sensors displayed on the screen.

    Result:

    Result
    		Proceed to
    All ECUs and sensors connected to the CAN communication system are displayed on the screen.
    (CAN bus circuit is currently normal.)
    		A
    One of the ECUs and sensors connected to the CAN communication system is not displayed on the screen.
    (Open in ECU or sensor branch wires, or communication interrupted)
    		B*1
    Some ECUs and sensors repeatedly appear and disappear from the screen, during this check.
    (Open in one side of ECU or sensor branch wires)
    		C
    1. All ECUs and sensors except the main body ECU connected to the CAN MS bus are not displayed on the screen.
    2. The main body ECU outputs DTC U1002.
    (Open in CAN MS bus main wire or short in CAN MS bus wire)
    		D
    All ECUs and sensors connected to the CAN MS bus are not displayed on the screen.
    (Open in main body ECU branch wire or main body ECU malfunction)
    		E
    NOTICE:
    1. The systems (ECUs, sensors) that adopt CAN communication vary depending on the vehicle and optional equipment. Check which systems (ECUs, sensors) are installed on the vehicle (COROLLA_ZRE142 RM000000WIB0BUX.html).
    2. Non-installed ECUs or sensors will not be displayed. Do not mistake them for being in the communication stop mode.
    3. The ECUs and sensors that repeatedly appear and disappear from the screen during this check are considered normal. (The response to the Techstream and the tester display are affected by signals output from other ECUs which have an open circuit in either of their CAN branch wires.)
    HINT:
    1. *1: See DTC Chart instead of Communication Stop Mode Table when some of the ECUs connected to the CAN MS bus are not displayed on the screen (COROLLA_ZRE142 RM000000WIB0BUX.html).
    2. The ECUs connected to the CAN MS bus are displayed on the screen by the main body ECU.


B.
GO TO COMMUNICATION STOP MODE TABLE

C.
GO TO OPEN IN ONE SIDE OF CAN BRANCH WIRE

D.
GO TO U1002 (CAN MS BUS)

E.
GO TO MAIN BODY ECU COMMUNICATION STOP MODE
A


4.RECHECK DTC
    HINT:
    1. Sometimes CAN communication system DTCs are output, but all the ECUs and sensors connected to the CAN communication system are displayed on the Techstream. In this case, CAN communication system history DTCs may indicate the cause of the problem.
    2. ECUs related to a problem in the CAN No. 1 bus will store DTCs to indicate communication malfunctions. The communication stop mode in the CAN No. 1 bus can be determined by comparing the combination of DTCs that has been set. Refer to the DTC combination table for the CAN No. 1 bus.
    3. The main body ECU will store communication error DTCs when the ECUs connected to the CAN MS bus cannot communicate, or if a network malfunction occurs.

    Result:

    Result
    		Proceed to
    Communication error DTCs other than the codes output from the main body ECU are output.
    (A malfunction occurred in the CAN No. 1 bus.)
    		A
    The main body ECU outputs CAN MS bus DTC U1002.
    (A malfunction occurred in the CAN MS bus.)
    		B
    The main body ECU outputs CAN MS bus DTC U0327.
    (A malfunction occurred in an ECU branch wire connected to the CAN MS bus.)
    		C


B.
GO TO "U1002 (CAN MS BUS)"

C.
GO TO "U0327"
A


5.DTC COMBINATION TABLE

  1. Confirm the problem according to the combination of output DTCs regarding the CAN communication system (COROLLA_ZRE142 RM000000WIB0BUX.html).

    HINT:
    CAN communication system history DTCs may indicate the cause if CAN communication system DTCs are output and all ECUs and sensors connected to the CAN communication system are displayed on "CAN Bus Check" screen of the Techstream.

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6.CIRCUIT INSPECTION

    NEXT


    7.IDENTIFICATION OF PROBLEM

      NEXT


      8.REPAIR OR REPLACE

        NEXT


        9.CONFIRMATION TEST

          NEXT

          END