LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2009 >> Impreza WRX, 4D Sedan >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Fuel Injection System (H4DOTC) >> Main Relay >> Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Main Relay: Inspection

  1. Measure the resistance between main relay terminals.
    Fig 1: Measuring Resistance Between Main Relay Terminals
    G06344745Courtesy of SUBARU OF AMERICA, INC.
    RESISTANCE REFERENCE CHART

    Terminal No. Standard
    1 and 2 1 MΩ or more
    3 and 4 130.4 - 230.8 Ω (When 20°C (68°F))
  2. Connect terminal No. 3 to the battery positive terminal and the No. 4 terminal to the battery ground terminal, and measure the resistance between the main relay terminals.
Fig 2: Measuring Resistance Between Main Relay Terminals
G06344746Courtesy of SUBARU OF AMERICA, INC.
RESISTANCE REFERENCE CHART

Terminal No. Standard
land 2 Less than 1 Ω