Cummins ISB4.5 CM2150 Fault Code: 731 PID: SID 64 SPN: 723 FMI: 7 Engine Speed/Position Camshaft and Crankshaft Misalignment – Mechanical System Not Responding or Out of Adjustment.

Circuit Description
The crankshaft position and camshaft position sensors are Hall effect type sensors. The engine control module (ECM) provides a +5 volt supply to the position sensor and a return circuit. As the teeth on the crankshaft speed ring or the lobes on the camshaft gear move past the position sensor, a signal is generated on the position sensor signal circuit. The ECM interprets this signal and converts it to an engine speed. A missing tooth on the crankshaft gear is used to determine the position of the engine by the ECM.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes
The ECM detects that the crankshaft position does not match the camshaft position signal input to the ECM.

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE light and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code
-To validate the repair, start the engine and let it idle for 1 minute.
-The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.
-The ECM will turn off the malfunction indicator lamp (MIL) after three consecutive ignition cycles that the diagnostic runs and passes.
-This fault code and malfunction indicator lamp (MIL) can also be cleared with INSITE™ electronic service tool.

Shop Talk
The ECM monitors the position of the missing tooth on the crankshaft speed sensor target and the camshaft speed sensor target. If the two positions do not match, the ECM then determines that there is a mechanical misalignment between the two sensors.

Possible Causes
-Engine speed sensor rings that are loose or not aligned correctly
-Mechanical misalignment