Volvo FH MID 128 PID 103 | Turbocharger Speed Sensor Fault & Derate Fix

Is your Volvo FH losing power and throwing the MID 128 PID 103 fault code? In this episode of Machine Logic HQ, we break down the exact algorithmic logic behind the Turbocharger Shaft Speed Sensor Fault. When this sensor misbehaves, the Engine Control Unit (ECU) triggers a derate mode to protect the engine from over speeding. Don't just throw parts at the truck! Follow our step-by-step diagnostic checklist to find the root cause, from simple sensor cleaning to harness testing. 📋 DIAGNOSTIC CHECKLIST COVERED: 1. Sensor Tip Inspection (Carbon buildup & mechanical damage) 2. Wiring Harness & Connector Check (Heat damage & pin corrosion) 3. 5-Volt ECU Reference Supply Measurement 4. Turbocharger Shaft Axial Play Inspection If this deep dive helped you understand your Volvo FH diagnostic logic, make sure to LIKE the video and SUBSCRIBE to the channel. We are breaking down heavy truck fault codes piece by piece! #VolvoFH #MID128PID103 #MachineLogicHQ #TruckMechanic #HeavyTrucks #VolvoTrucks #DiagnosticLogic