2008 Subaru Outback Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Section 12 (Starting/Charging Systems (H4SO)): Generator: Inspection: Diode

WARNING: This page is about a different car, the 2006 Subaru Outback and 2006 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: There is the possibility of damaging the diodes if a mega-tester (used to measure high voltages) or a similar measuring instrument is used. Never use a mega tester or equivalent for this test.
  1. Check the positive diode

    Check for continuity between the diode lead and positive side heat sink. If resistance is 1 Ξ© or less only in the direction from the diode lead to the heat sink, the positive diode is OK.

    Fig 1: Checking Positive Diode
    G05017468
  2. Check negative diode

    Check for continuity between the negative side heat sink and diode lead. If resistance is 1 Ξ© or less only in the direction from the heat sink to the diode lead, the negative diode is OK.

    Fig 2: Checking Negative Diode
    G05017469
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.