2012 Subaru Outback Base, Automatic CVT TransFACTORY OEM SERVICE PROCEDURE

Check Key Warning Switch

Step Check Yes No
1 CHECK KEY WARNING SWITCH. 
  1. Prepare the Subaru Select Monitor kit.
  2. On << System Selection Menu >> display, select {Integ. unit mode}.
  3. Select the {Current Data Display & Save}.
  4. Select the {key-lock warning SW}.
 Is the normal input signal displayed when the key is inserted in/removed from the ignition switch? The key warning switch is OK. Go to step 2  .
2 CHECK FUSE. 
Remove and visually check fuse No. 18 (in the main fuse box).		 Is the fuse blown out? Replace the fuse with a new part. Go to step 3  .
3 CHECK KEY WARNING SWITCH CIRCUIT. 
  1. Disconnect the connector of body integrated unit.
  2. Insert the key into ignition switch. (LOCK position)
  3. Measure the voltage between body integrated unit connector and chassis ground.

    Connector & terminal 

    (B280) No. 4 (+) - Chassis ground (-): 

 Is the voltage 10 V or more? Go to step 4.  Go to step 5  .
4 CHECK KEY WARNING SWITCH CIRCUIT. 
  1. Remove the key from ignition switch.
  2. Measure the voltage between body integrated unit connector and chassis ground.

    Connector & terminal 

    (B280) No. 4 (+) - Chassis ground (-): 

 Is the voltage less than 1 V? Replace the body integrated unit. Refer to , BODY INTEGRATED UNIT . Go to step 5  .
5 CHECK KEY WARNING SWITCH. 
  1. Disconnect the key warning switch connector.
  2. Insert the key into ignition switch. (LOCK position)
  3. Measure the resistance between key warning switch terminals.

    Connector & terminal 

    (B350) No. 3 - No. 4: 

 Is the resistance less than 1 Ω? Go to step 6.  Replace the key warning switch.
6 CHECK KEY WARNING SWITCH. 
  1. Remove the key from ignition switch.
  2. Measure the resistance between key warning switch terminals.

    Connector & terminal 

    (B350) No. 3 - No. 4: 

 Is the resistance 1 MΩ or more? Check the following:
  • Harness for open circuits or shorts between the key warning switch and fuse.
  • Harness for open or short between the body integrated unit and key warning switch
 Replace the key warning switch.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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