04 September, 2025Detroit DD13 EPA07 (2007-09) Fault Code: SPN 94 FMI 4 (MCM) Low Side Fuel Pressure Sensor Circuit Failed Low NOTE: Please see the step by step troubleshooting procedures for this specific code. PROBABLE CAUSES:1. Low pressure pump outlet (LPPO) fuel pressur sensor.2. LPPO fuel pressure sensor wiring/connector. Share on Facebook Opens in a new window. Tweet on Twitter Opens in a new window. Pin on Pinterest Opens in a new window. Back to blog