Abstract: An electronic control device 1 includes: a circuit board 4 having a first surface 4A on which heat-generating components 21, 22, 23 and heat-degradable components 31, 32 are mounted; a first metallic case 2 covering the first surface 4A; a second case 3 covering a second surface 4B of the circuit board 4 opposite to the first surface 4A; supporting members 51, 52 provided between the heat-degradable components 31, 32 and the first case 2 to support the heat-degradable components 31, 32; and heat-dissipating members 41, 42, 43, each provided on at least any of the heat-generating components 21, 22, 23, and the first case 2, to transmit heat generated from the heat-generating component 21, 22, or 23, to the first case 2. A heat conductivity of the heat-dissipating members 41, 42, 43 is higher than a heat conductivity of the supporting members 51, 52.

Abstract: An engine fluid heating apparatus, preventing failure in heating fluid, is provided. A control device opens a sub switch during an initial opening period (“IOP”) after closing a main switch, and the control device closes the sub switch during an initial closing period (“ICP”) after the IOP. Circuit normality is displayed by turning on an indicator lamp when a heater feeding circuit is electrically conducted via a bypass electric circuit during the IOP. Heater feeding is displayed by turning off the indicator lamp when power is supplied to the electric heater via a trunk electric circuit during the ICP. Circuit abnormality is displayed by turning off the indicator lamp when the heater feeding circuit is not electrically conducted via the bypass electric circuit during the IOP, and the circuit abnormality display is held by keeping the indicator lamp off during the ICP immediately after the IOP.

Abstract: An engine fluid heating apparatus, preventing failure in heating fluid, is provided. A control device opens a sub switch during an initial opening period (“IOP”) after closing a main switch, and the control device closes the sub switch during an initial closing period (“ICP”) after the IOP. Circuit normality is displayed by turning on an indicator lamp when a heater feeding circuit is electrically conducted via a bypass electric circuit during the IOP. Heater feeding is displayed by turning off the indicator lamp when power is supplied to the electric heater via a trunk electric circuit during the ICP. Circuit abnormality is displayed by turning off the indicator lamp when the heater feeding circuit is not electrically conducted via the bypass electric circuit during the IOP, and the circuit abnormality display is held by keeping the indicator lamp off during the ICP immediately after the IOP.