Diagnostic Overview
Volvo fault entry PID 94 FMI 1 appears to be a PID/FMI-style code and should be verified with the full OEM definition. PID 94 is commonly associated with fuel delivery or fuel pressure data on many heavy-duty systems, and an FMI 1-style condition often indicates a low reading. If active, this can cause low power, hard starting, hesitation, or engine protection depending on operating conditions.
Likely Causes
Restricted fuel filters; low fuel supply pressure; air in fuel; weak pump; sensor wiring issue; fuel pressure sensor problem; contaminated fuel.
What To Check First
Verify the exact PID/FMI in Tech Tool, inspect filters, check fuel supply pressure, look for air in fuel, and compare commanded versus actual fuel data.