Cummins ISB CM850 (2003-06) Fault Code: 731 (Auto) PID: SID 64 SPN: 732 FMI: 7 Engine Speed Sensor/Position Camshaft and Crankshaft Misalignment – Mechanical System Not Responding Properly or Out of Adjustment. Mechanical misalignment between the crankshaft and camshaft engine speed sensors.

This fault will become active anytime the ECM receives a signal from both the primary EPS (crankshaft sensor) and the backup EPS (camshaft sensor), and the ECM determines that the camshaft and crankshaft signals are not in the correct phase. If this fault code is active immediately following a repair that included camshaft removal, it is likely that the camshaft gear was installed incorrectly and is not timed correctly.

The sensor return configuration for Euro 4 ISB engines has been changed for automotive wiring harnesses manufactured from February 2012 onward. The new style wiring harnesses can be be identified using the method below:

1)Disconnect the ECM connector
2)Disconnect the camshaft position sensor
3)Disconnect the intake manifold pressure/temperature sensor
4)Check for continuity between the intake manifold pressure/temperature sensor RETURN pin and the camshaft position sensor RETURN pin
5)Check for continuity between ECM pin 47 and the camshaft position sensor RETURN pin
6)Use the table below to determine which harness is fitted to the engine.

NOTE: QSB engines, all C series engines, and all L series engines are not affected by this change.

Possible repairs:

1)Replace the camshaft position sensor. Refer to Procedure 019-363 in Section 19.
2)Replace the crankshaft position sensor.
3)Replace the tone wheel.
4)Replace, tighten, or clean the ground wires or connections.
5)Remove and install camshaft to properly align timing marks at TDC.
6)Replace the crankshaft assembly