BRACKET AS 3893441 - Caterpillar

ECM automatically compensates for engine operation at higher elevations. The electronic control system derates the fuel delivery. The fuel delivery is a function of barometric pressure. The barometric pressure is sensed by the system's atmospheric pressure sensor. The engine power is derated at the rate of 1 percent per 305 m (1001 ft). The maximum derating of the engine is 24 percent. The derating maximum fuel delivery maintains exhaust temperatures within acceptable limits over a full range of altitudes. Derating by the ECM begins at a specific elevation. The rate of derating is based upon atmospheric pressure. The elevation for beginning derating can be found in the TMI (Technical Marketing Information).If the ECM senses an incorrect signal from the atmospheric pressure sensor and the turbocharger inlet pressure sensors, then the electronic control system will impose the maximum altitude derating. The maximum altitude derating will be imposed until the problem is corrected.