An engine control unit (ECU) includes a housing, a cover sealingly engaged with the housing, a circuit board disposed in the housing and support structure disposed in the housing and associated with an inner surface of the cover. At least one fastener couples both the support structure and the circuit board to the housing. An adhesive bonds at least portions of the support structure to portions of the inner surface of the cover. The support structure is constructed and arranged to limit deflection of the cover when internal pressure increase in the ECU.