LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 1991 >> ES 250 Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Relays >> Circuit Opening Relay
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit Opening Relay

NOTE: For more LS400 information, see FUEL SYSTEM CIRCUIT diagnosis chart at end of article. See CIRCUIT DIAGNOSIS CHARTS .
  1. Turn ignition off. Circuit opening relay is located under engine ECU on ES250 and on right side of engine ECU on LS400. Remove relay from vehicle. Using an ohmmeter, check for continuity between relay terminals STA and E1 on ES250 or ST and E1 on LS400. See Fig 1 & 10. Check for continuity between terminals B and FC on ES250 or IG and FC on LS400. Ensure continuity does not exist between terminals B and FP. If continuity is not as specified, replace relay.
  2. Apply battery voltage between terminals STA and E1 on ES250 or ST and E1 on LS400. Using an ohmmeter, ensure continuity is present between terminals B and FP. Apply battery voltage between terminals B and FC on ES250 or IG and FC on LS400. Ensure continuity is present between terminals B and FP. If continuity is not as specified, replace relay.
Fig 1: ES250 Circuit Opening Relay Terminal ID
G90C18855Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: LS400 Circuit Opening Relay Terminal ID
G91E16315Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002