CAN COMMUNICATION SYSTEM Transmission Control ECU Communication Stop Mode

DESCRIPTION

The transmission control ECU drives the parking lock actuator in accordance with signals from the power management control ECU.

Detection Item Symptom Trouble Area
Transmission Control ECU Communication Stop Mode

Either condition is met:


  • Communication stop for "Transmission Control" is indicated on the "Communication Bus Check" screen of the GTS.

  • Communication system DTCs (DTCs that start with U) that correspond to "Transmission Control ECU Communication Stop Mode" in "DTC Combination Table" are output.

  • Transmission control ECU assembly branch line or connector

  • Power source circuit of transmission control ECU assembly

  • Transmission control ECU assembly

WIRING DIAGRAM

B001MTAE21

CAUTION / NOTICE / HINT

Note


  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

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  • Before measuring the resistance of the CAN bus, turn the power switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

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  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

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  • Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips


  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.

  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS LINES (TRANSMISSION CONTROL ECU ASSEMBLY BRANCH LINE)


    1. Disconnect the cable from the negative (-) auxiliary battery terminal.

    2. B001L17E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Transmission Control ECU Assembly)

      Disconnect the A22 transmission control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A22-16 (CA1H) - A22-15 (CA1L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (TRANSMISSION CONTROL ECU ASSEMBLY)

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. B001M23E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Transmission Control ECU Assembly)

      Disconnect the A21 transmission control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A22-1 (E1) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

    3. Reconnect the cable to the negative (-) auxiliary battery terminal.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A21-16 (+B) - Body ground Power switch on (IG) 11 to 14 V

    OK

    REPLACE TRANSMISSION CONTROL ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)