SEAL 5084421 - Caterpillar

protection is automatically activated when the Electronic Control Module (ECM) on the transmission determines that the machine is digging. Once the axle protection is enabled, the ECM on the transmission sends a transmission requested engine speed limit to the ECM on the engine in order to control the engine speed. The purpose of this feature is used to control the torque that is delivered through the power train while the machine is digging. This control of the torque will balance the machine's capabilities with the performance requirements. By controlling the engine speed, the power train control is able to manage the loads on the power train. Managing the loads of the power train extends the life to the power train. Managing the loads of the power train also enhances the performance of digging.The transmission requested engine speed limit varies on the following factors: torque converter speed ratio, implement fixed pump hydraulic pressure and left pedal position.When axle protection is not activated, the transmission increases the requested speed limit.Note: Observers will notice two different engine stall speeds during a torque converter stall check. One stall speed will be measured when this feature is active. Another stall speed will be measured when this feature is not active.Refer to the Power Train Electronic Control System Service Manual for complete information.