New Holland ENG 731 – Engine Controller (ENG) / Engine Control Module (ECM): Engine Speed / Position #2 - Mechanical misalignment

This code indicates a synchronization error or mechanical misalignment between the camshaft position sensor and the crankshaft position sensor. The engine control module relies on a precise ratio (typically 2:1) between the crankshaft and camshaft to manage fuel injection and ignition timing. When the signals from these two sensors fall out of their expected boundaries (often due to physical timing slack or sensor failure), the system logs this mechanical misalignment fault.

• T4
• T5
• T6
• T7
• T8
• T9
• T9.390
• T9.600
• T7.170
• T4.105
• CR Series
• CX Series
• CR9090
• CX8080
• CX8090
• C232
• C238

1. 1

   Inspect the wiring harnesses and connectors for both the camshaft and crankshaft position sensors for loose connectors, dirty contacts, misaligned pins, or damaged wires.

2. 2

   Verify that the 5V reference voltage and ground connections are present and stable at the sensor connectors using a multimeter.

3. 3

   Remove the sensors and check for physical damage, metal shavings, or debris on the magnetic pickup tips.

4. 4

   Check for physical timing misalignment, such as worn timing gears, excessive slack in the timing chain/belt, or a stuck/damaged camshaft phaser.

1. 1

   Disconnect Power

   Disconnect the machine's battery to prevent electrical shorts during the repair.

2. 2

   Replace Faulty Sensor(s)

   If diagnostics point to a failed sensor, locate the camshaft sensor (usually on the timing cover or cylinder head) or the crankshaft sensor (usually on the cylinder block near the flywheel/crank pulley). Remove the mounting bolt, pull out the old sensor, lubricate the O-ring on the new sensor, and install it securely.

3. 3

   Address Mechanical Timing

   If the sensors are functioning properly but the code persists, the engine timing cover must be removed to inspect the timing gears/chain. Replace any worn timing components and ensure the timing marks on the crankshaft and camshaft gears are perfectly aligned according to the OEM service manual.

4. 4

   Clear the ECM

   Reconnect the battery. After replacing the sensor or correcting the timing, the error code must be manually cleared from the ECM using a diagnostic scanner (or via the machine's specific key-cycling procedure).

5. 5

   Perform an ECM Relearn

   Execute an ECM 'relearn' or synchronization procedure via the diagnostic tool to reset the baseline synchronization between the new sensor readings.