What are the main relay circuits in a Toyota?
Toyota utilizes several different EFI Main Relay circuits depending on application. These circuits can be categorized into four distinct types. 1) Dual contact EFI Main Relay, ignition switch controlled 2) Single contact EFI Main Relay, ignition switch controlled 3) Dual EFI Main Relays, ignition switch or ECU controlled
How can you tell if a Toyota relay is open or closed?
You can test the relays with battery voltage, and a continuity tester or automotive light bulb and socket. Simply power up the primary circuit with the battery, and then check the secondary circuit to see if it’s open or closed.
How does the circuit opening relay ( Cor ) work?
Circuit Opening Relay (COR) has two normally-open contacts (open when no power is applied). Coil 1 of COR is energized by IGN switch while in START position.
What happens when you cut power to the relay?
When the primary circuit is powered, a Normally-Open relay closes the secondary circuit. Cut power to primary, and the secondary side returns to its state of being normally open.
Where is the main relay on an EFI system?
Because the EFI Main Relay supplies battery voltage to the +B terminal of the check connector when the ignition switch is in the run position, this is an excellent place to perform a quick check of the relay function. Dual Contact (Single Relay), Ignition Switch Controlled This EFI Main Relay configuration is used on the Conventional eFi system.
Why does my truck EFI relay get hot?
No avail, the relay still gets hot after a few mins of run time. The truck runs fine, the EFI fuse hasn’t blown (I’ve taken the truck on a few long range runs, 2hrs+ of constant run time), just the hot relay.
What kind of relay is used for ignition switch?
Dual Contact (Single Relay), Ignition Switch Controlled This EFI Main Relay configuration is used on the Conventional eFi system. It uses separate power contacts to supply current to the fuel injector/ignition circuits and the ECU/circuit opening relay circuit. This limits current flow that the ECU power contact must handle.
Why is the EFI main relay in the ignition?
Because the EFI Main Relay supplies battery voltage to the +B terminal of the check connector when the ignition switch is in the run position, this is an excellent place to perform a quick check of the relay function.
What are the symptoms of a bad ECM power relay?
A bad relay may cause the vehicle to crank, but not start, or sometimes not even crank at all. 3. Battery drain or dead battery. A failed ECM power relay can also cause a battery drain or dead battery. If the relay shorts it can leave power on to the computer, even when the vehicle is turned off.
What kind of wiring is in a 1986 Toyota 4Runner?
1986 Toyota 4runner Rear Window Wiring Diagram Back 1986 Toyota Headlight Wiring Diagram Schematic User Diagrams Plaster 1985 Ford Truck Wiring Diagram Home Diagrams Producer 1989 Toyota Pickup 22 Re The Oxygen Sensor Plug Male End Was Lost During Installiation Of Another Motor From 1985 Toyota Pickup Truck Hilux 4runner Wiring Diagram
How does the engine control module ( ECM ) work?
The ECM takes the information from the engine’s various sensors, and uses that information to calculate and tune engine spark and fuel for maximum power and efficiency. The ECM plays a crucial role in newer vehicles, where many (if not all) of the essential functions of the car are controlled by the ECM.
What are the signs of a failing ECM?
Common signs of a failing PCM/ECM/ECU include the Check Engine Light coming on, engine performance issues, and the car not starting. 1. Check Engine Light Turns On 2. Engine Stalling or Misfiring 3. Engine Performance Issues 4. Car Not Starting