SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSSUBARU2007LEGACY I, 4D WAGON, AUTOMATICREPAIR AND DIAGNOSISACCESSORIES & EQUIPMENTANTI-THEFT SYSTEMSIMMOBILIZER (DIAGNOSTICS)DIAGNOSTICS CHART FOR SECURITY INDICATOR LIGHTCHECK KEY SWITCH CIRCUITWIRING DIAGRAM
2007 Subaru Legacy i, 4D Wagon, Automatic

Check Key Switch Circuit: Wiring Diagram

2007 Subaru Legacy i, 4D Wagon, AutomaticSECTION Wiring Diagram
Fig 1: Key Switch - Wiring Diagram
G05344152Courtesy of SUBARU OF AMERICA, INC.
DIAGNOSTIC PROCEDURE CHART

Step Check Yes No
1 CHECK POWER SUPPLY CIRCUIT. 
  1. Disconnect the harness connector from key warning switch.
  2. Turn the ignition switch to "ACC" or "LOCK" (with key inserted).
  3. Measure the voltage between key warning switch harness connector terminal and chassis ground.

    Connector & terminal 

    (B350) No. 3 (+) - Chassis ground (-): 

 Is the voltage 10 V or more? Go to step 2.  Check the harness for open circuit or short between the key warning switch and fuse.
2 CHECK KEY WARNING SWITCH. 
  1. Insert the ignition key into the ignition switch. (OFF or ACC)
  2. Measure the resistance between key warning switch connector terminals.

    Connector & terminal 

    No. 3 - No. 4: 

 Is the resistance less than 1 Ω? Go to step 3.  Replace the key warning switch.
3 CHECK KEY WARNING SWITCH. 
  1. Remove the ignition key from the ignition switch.
  2. Measure the resistance between key warning switch connector terminals.

    Connector & terminal 

    No. 3 - No. 4: 

 Is the resistance 1 MΩ or more? Go to step 4.  Replace the key warning switch.
4 CHECK HARNESS BETWEEN KEY WARNING SWITCH AND BODY INTEGRATED UNIT. 
  1. Disconnect the harness connector from key warning switch.
  2. Disconnect the harness connector from body integrated unit.
  3. Measure the resistance between key warning switch harness connector terminal and body integrated unit harness connector terminal.

    Connector & terminal 

    (B350) No. 4 - (B281) No. 7: 

 Is the resistance less than 10 Ω? Replace the body integrated unit <Ref. to BODY INTEGRATED UNIT .> and replace all the ignition keys (including transponder). Execute the registration procedure next. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER". Repair the harness between key warning switch and body integrated unit.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

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.