2008 Subaru Outback Limited, StandardFACTORY OEM SERVICE PROCEDURE

Mechanism & Function -- Speed Control System (H4SO): General

An electronically controlled throttle is adopted.

The movement of the accelerator pedal is converted into electrical signals by the accelerator pedal position sensor and these signals are sent to the ECM.

The ECM controls the operation of the throttle body based on the signals from the accelerator pedal position sensor and on other driving conditions.

Fig 1: Identifying Accelerator Pedal Position Sensor
G03834207Courtesy of SUBARU OF AMERICA, INC.
Factory Service Tools

Use the Manual With the Right Hardware

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

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.