What does MSP code 984 indicate about the APU?

The MSP code 984 signifies that the Auxiliary Power Unit (APU) needs servicing. This code is used to alert personnel that while the APU may not be malfunctioning, it's essential to perform scheduled maintenance or checkups to ensure optimal performance. Regular servicing typically includes tasks like checking fluid levels, inspecting filters, and verifying the operational condition of various components. By attending to the servicing needs indicated by this code, the reliability and efficiency of the APU can be maintained, thus preventing more significant issues down the line. Recognizing and addressing these maintenance indicators is crucial for the continued operation of the APU and the overall performance of the aircraft.