ECM Power Source Circuit: Description

When the power switch is turned on (IG), the battery voltage is applied to terminal IGSW of the hybrid vehicle control ECU. The hybrid vehicle control ECU MREL output signal causes a current to flow to the coil, closing the contacts of the IGCT relay and supplying power to terminal +B of the hybrid vehicle control ECU.

If the power switch is turned off, the hybrid vehicle control ECU holds the IGCT relay ON for a maximum of 2 seconds to allow for the initial setting of the throttle valve.

When the power switch is turned on (IG), voltage from the hybrid vehicle control ECU MREL terminal applies to the IGCT relay. This causes the contacts of the IGCT relay to close, which supplies power to terminal +B or +B1 of the hybrid vehicle control ECU.