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Standby Current

  1. Prepare the circuit tester which can measure down to 1 mA.
    NOTE: For model with keyless access function, the standby current changes regularly. Therefore, prepare the analog type circuit tester.
  2. Using the circuit tester, check the standby current.
NOTE: The standby current may be displayed lower than the actual value if the battery is weak, so charge or replace the battery as necessary.
  1. Check the battery.

    Appearance: 

    Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>Battery>INSPECTION>APPEARANCE .

    Electrolyte level: 

    Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>Battery>INSPECTION>ELECTROLYTE LEVEL .

    Specific gravity of electrolyte: 

    Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>Battery>INSPECTION>SPECIFIC GRAVITY OF ELECTROLYTE .

  2. Check that the fuse is not blown out and is properly inserted.
  3. When non-genuine electrical parts (including parts sold in authorized workshops) are installed, remove all parts.
  4. Check that back-up fuse is inserted. Ref. to PRE-DELIVERY INSPECTION>PRE-DELIVERY INSPECTION (PDI) PROCEDURE>FUSE INSTALLATION .
  5. Start the engine, and set the switch positions for each system as shown in the following table.
    NOTE: Some of the listed systems are not equipped depending on the vehicle. Set only the systems equipped on the vehicle to the positions as shown.
    System Position
    Headlight ON or Auto
    Fog light ON
    Wiper (front and rear) ON or Low speed
    Audio and navigation system ON
    Rear defogger ON
    Room light DOOR
    Luggage light DOOR
    Map light OFF
    Auto A/C ON (AUTO)
    Manual A/C ON (Speed 1)
    Electronic parking brake ON
    Electrical parts other than listed above (electrical parts that users can confirm the operation with the key removed) OFF
  6. Turn the ignition switch to OFF.
  7. Operate the front hood lock release lever to unlock the front hood.
  8. Close all the doors (including rear gate) and then lock the doors. (Security alarm is in set condition)
    NOTE: For model with keyless access function, take the access key 1.5 m or more away from the vehicle after the door lock. And do not put the access key close to the vehicle while measuring the standby current.
  9. Wait for 5 minutes after door lock until the standby current stabilizes.
  10. Loosen the nut which holds the ground terminal to the battery sensor.
    NOTE: Do not remove the ground terminal.
    G13198034Courtesy of SUBARU OF AMERICA, INC.
  11. Connect the circuit tester positive terminal to the ground terminal.
    NOTE: To prevent the damage to the circuit tester, set the circuit tester range to a large value first, then gradually change it to smaller values.
  12. Connect the circuit tester negative terminal to the ground terminal installation part of the battery sensor.
  13. While connecting the circuit tester positive terminal with the ground terminal as shown in the figure, remove the ground terminal from the battery sensor.
    G13199266Courtesy of SUBARU OF AMERICA, INC.
  14. Check the standby current.
    CAUTION: If the terminals and circuit tester are detached during standby current inspection, reconnect the ground terminal to the battery sensor and repeat the procedure from step (9).
    NOTE:
    • For model with keyless access function, the standby current changes periodically because the keyless access system continuously searches the access key (polling).
    • When measuring the standby current, the reading of the circuit tester oscillates. Therefore, read the average value (median value).
    • The standby current may become large when the vehicle system (ELCM) is activated 5 times at 30-minute intervals or 5 hours after turning the ignition switch to OFF.
    NOTE: Therefore, the measurement should be completed in 20 minutes after the ignition switch is turned to OFF.
    NOTE: If it takes more than 20 minutes, start the engine once, turn the ignition switch to OFF again, then perform the inspection.
    G13863098Courtesy of SUBARU OF AMERICA, INC.

    Check

    • When the maximum measurement value is less than 70 mA → Standby current is normal.
    • When the maximum measurement value is 70 mA or more → Go to step (15).
  15. Connect the ground terminal to the battery sensor, and wait for 55 minutes.
    NOTE: For 55 minutes after turning the ignition switch to OFF, the vehicle system (EPS) may still be active.
  16. Measure the standby current with the same measurement procedures as in steps (10) through (14).

    Check

    • When the maximum measurement value is less than 70 mA → Standby current is normal.
    • When the maximum measurement value is 70 mA or more → Go to step (17).
  17. Remove all fuses one by one to identify which system changes the standby current value significantly. Ref. to WIRING SYSTEM>POWER SUPPLY CIRCUIT .
  18. Check the related part, harness and connector of the system whose standby current has changed significantly.
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