23 June, 2025Cummins ISM CM870 (2003-06) Fault Code: 731 PID: S064 SPN: 723 FMI: 7/7 Engine Speed Sensor and Camshaft Position Sensor – Mechanical Misalignment Between Camshaft and Crankshaft Sensors. Possible causes: 1)Loose, missing, or corroded grounds2)Damaged tone wheel teeth3)Loose crankshaft tone wheel4)Static timing misset5)Front gear train slippage6)Misoriented engine speed or camshaft position sensor7)Electrical noise. Possible repairs: 1)Replace the speed or position sensor.2)Replace the crankshaft or injector camshaft, whichever has malfunctioned. 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