This study analyzes the automotive behavior and its impact on driving safety when the Micro controller Unit (Micom), a core component of the automotive Engine Control Unit (ECU), is exposed to high temperatures. The automotive behavior was observed with and without the ECU housing cover under thermal exposure, and the temperature of the Micom was determined using heat transfer principles. The results showed that with the housing cover in place, a thermal equilibrium was maintained at approximately 160[°C], and the Micom's temperature was about 73[°C], which is within its guaranteed operating limits and did not affect the automotive behavior. When the housing cover was removed, the engine stoped to operate at approximately 220[°C], and it is presumed that the Micom's internal circuitry was damaged. These findings can provide useful quantitative data for future reliability assessments of ECUs and for investigations into sudden unintended acceleration phenomena.

This study investigates the impact of both direct and indirect moisture ingress into an automotive engine control unit(ECU) on vehicle behavior and operational safety. Two experimental conditions were examined: exposure to an environment with 100% relative humidity(indirect ingress) and direct injection of 1.0~2.0 cc of water onto the ECU(direct ingress). The results showed no abnormal behavior under indirect moisture conditions. However, direct moisture ingress caused engine malfunctions, warning light activations, and irregular vehicle behavior. Notably, the vehicle's safety logic functioned as intended, resulting in engine shutdown without leading to unintended acceleration. These findings provide quantitative data valuable for future reliability assessments of ECUs and investigations into sudden unintended acceleration phenomena.