Battery Signal (Corolla)
WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2002 Toyota Tundra, 2002 Toyota Tacoma, 2002 Toyota Sienna, 2002 Toyota Sequoia, and 2002 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
Battery voltage is always present at BATT terminal of Engine Control Module (ECM). When ignition is turned on, voltage for ECM operation is applied through EFI main relay to +B terminal on ECM. EFI main relay may also be referred to as EFI relay or F-HTR relay.