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Power Unit Can

Trouble causes: 

Wiring diagram: 

CAN communication system Ref. to WIRING SYSTEM>CAN COMMUNICATION SYSTEM>WIRING DIAGRAM .

G16447147Courtesy of SUBARU OF AMERICA, INC.
G16447148Courtesy of SUBARU OF AMERICA, INC.
CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to LAN SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .
NOTE:
  • When measuring the resistance of CAN communication circuit, measure it in sleep status.

    To enter sleep status

    • With ignition switch OFF and key or switch operation stopped, keep the doors, trunk, and rear gate all closed for one minute or more.
    • On model with the keyless access with push button start, keep the access key 2 m or more away from the vehicle.
  • When the bus line is measured, combined resistance of end resistance (120 Ω) in ECM and end resistance (120 Ω) in the central gateway control module can be measured. The combined resistance is more than 52 Ω and less than 62 Ω with the stabilizing circuit included. If the measured resistance value becomes 52 Ω or less, main wiring harness or related lines may be shorted. Or, the combined resistance may have changed because of a resistance other than the end resistance created on the circuit. If the measured value is 62 Ω or more, there may be a malfunction such as open circuit in one of the end resistances, in the stabilizing circuit, or in the main wiring harness.

    Also, even when the resistance value falls more than 52 Ω and less than 62 Ω, related lines may be open if an error of communication for initializing or a CAN system U-code has occurred. (The resistance cannot be more than 52 Ω and less than 62 Ω if the main wiring harness is open.)

  1. CHECK BASIC DIAGNOSTIC PROCEDURE  .

    Check that the basic diagnosis has been performed up to STEP  3.

    NOTE: Possible defective parts can be narrowed easily by inspection using Subaru Select Monitor before performing "CHECK CAN COMMUNICATION CIRCUIT" using a tester.

    Was the basic diagnostic procedure performed?

    Yes:  Go to  2.

    No:  Perform the basic diagnostic procedure. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

  2. CHECK FOR SHORT TO GROUND IN POWER UNIT CAN COMMUNICATION CIRCUIT  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the central gateway control module connector.
    3. Using a tester, measure the resistance between the central gateway control module connector and chassis ground.

      Connector & terminal 

      (i366) No. 23 - Chassis ground:

      (i366) No. 24 - Chassis ground:

    Is the resistance less than 10 Ω?

    Yes:  Check for ground short. Ref. to LAN SYSTEM (DIAGNOSTICS)>CAN COMMUNICATION CIRCUIT CHECK>INSPECTION>GROUND SHORT INSPECTION (POWER UNIT CAN) .

    No:  Go to  3.

  3. CHECK FOR SHORT TO POWER SUPPLY IN POWER UNIT CAN COMMUNICATION CIRCUIT  .
    1. Turn the ignition switch to ON.
    2. Using a tester, measure the voltage between the central gateway control module connector and chassis ground.

      Connector & terminal 

      (i366) No. 23 (+) - Chassis ground (-):

      (i366) No. 24 (+) - Chassis ground (-):

    Is the voltage 5 V or less?

    Yes:  Go to  4.

    No:  Check for power supply short. Ref. to LAN SYSTEM (DIAGNOSTICS)>CAN COMMUNICATION CIRCUIT CHECK>INSPECTION>POWER SHORT INSPECTION (POWER UNIT CAN) .

  4. CHECK FOR SHORT IN POWER UNIT CAN COMMUNICATION CIRCUIT  .
    1. Turn the ignition switch to OFF.
    2. Using a tester, measure the resistance between the central gateway control module connector terminals.

      Connector & terminal 

      (i366) No. 23 - (i366) No. 24:

    Is the resistance 52 Ω or less?

    Yes:  Perform the inspection for resistance of 52 Ω or less. Ref. to LAN SYSTEM (DIAGNOSTICS)>CAN COMMUNICATION CIRCUIT CHECK>INSPECTION>52 Ω OR LESS (POWER UNIT CAN) .

    No:  Go to  5.

  5. CHECK FOR OPEN CIRCUIT IN POWER UNIT CAN COMMUNICATION CIRCUIT  .

    Using a tester, measure the resistance between the central gateway control module connector terminals.

    Connector & terminal 

    (i366) No. 23 - (i366) No. 24:

    Is the resistance 62 Ω or more?

    Yes:  Perform the inspection for resistance of 62 Ω or more. Ref. to LAN SYSTEM (DIAGNOSTICS)>CAN COMMUNICATION CIRCUIT CHECK>INSPECTION>62 Ω OR MORE (POWER UNIT CAN) .

    No:  If the display of CAN system U-code disappears from the current code, the CAN network is currently normal. If the U-code has detected as current code, related lines may be open. Perform the inspection for the related line corresponding to the detected DTC. Ref. to LAN SYSTEM (DIAGNOSTICS)>CAN COMMUNICATION CIRCUIT CHECK>LIST .

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