A system and method for activating on a user interface an indicator of a condition of a lubricant in a machine module. The system may comprise a controller and a user interface. The controller may be configured to, for each of a first time window and a second time window: receive a plurality of lubricant characteristics and measured lubricant temperatures, calculate an adjusted lubricant characteristic, and determine a slope based on the plurality of adjusted lubricant characteristics. The controller may further determine a change in slope, and generate a signal to activate the indicator on the user interface based on the change in slope, wherein, if the change in slope exceeds a threshold, the indicator is a lubricant changed indicator.