Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2018 Subaru Forester 2.0XT PremiumFACTORY OEM SERVICE PROCEDURE
Electrical Specification
- Model without push button ignition switch
Item Connector No. Terminal No. Input/Output signal Measured value and measuring conditions Battery power supply B281 6 9 - 16 V 7 i84 6 Ignition power supply B280 32 10 - 15 V when ignition switch is at ACC. B281 3 10 - 15 V when ignition switch is at ON or START. TCM ("P" range) i84 27 Can not be measured because of digital communication 35 Stop light and brake switch B280 10 9 - 16 V when the stop light & brake switch is ON.
0 V when the stop light & brake switch is OFF."P" range switch B281 18 Less than 1.5 V when select lever is in "P" range.
8 V or more when select lever is in positions other than "P" range.Solenoid unit signal B281 5 8.5 - 16 V when shift lock is released
0 V when shift lock is operating.Key warning switch signal B280 4 9 - 16 V when key is inserted.
0 V when key is removed.Key lock solenoid signal B281 4 7.5 - 16 V when the key is inserted with the select lever shifted in positions other than "P" range.
0 V at other conditions than above.Ground B280 1 - i84 1 - Model with push button ignition switch
Item Connector No. Terminal No. Input/Output signal Measured value and measuring conditions Battery power supply B281 6 9 - 16 V 7 i84 6 Ignition power supply B280 32 10 - 15 V when ignition switch is at ACC. B281 3 10 - 15 V when ignition switch is at ON or START. TCM ("P" range) i84 27 Can not be measured because of digital communication 35 Stop light and brake switch B280 10 9 - 16 V when the stop light & brake switch is ON.
0 V when the stop light & brake switch is OFF."P" range switch B281 18 Less than 1.5 V when select lever is in "P" range.
8 V or more when select lever is in positions other than "P" range.Solenoid unit signal B281 5 8.5 - 16 V when shift lock is released
0 V when shift lock is operating.Ground B280 1 - i84 1
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
