John Deere 637.07 – Engine Control Unit (ECU): Crank Position/Cam Position Out of Sync

The engine controller is detecting that the timing signal from the crankshaft position sensor does not align correctly with the signal from the camshaft position sensor or the high-pressure fuel pump position sensor. This can be caused by a failing sensor, damaged wiring, or an actual mechanical timing issue (such as a slipped gear or incorrectly mounted pump).

• 5085E
• 5090E
• 5090EL
• 5100E
• 5065M
• 5075M
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5095M
• 5095MH
• 5105M
• 5015ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• PowerTech 4.5L (4045)
• PowerTech 6.8L (6068)
• PowerTech 9.0L (6090)
• PowerTech 10.5L
• PowerTech 12.5L
• 7930
• 9230
• 9330
• 9430
• 9530
• 9630
• 444J
• 544J
• 624J
• 750J
• 850J
• 319D
• 120
• 130G
• 160C
• 210G
• 450J
• 764

1. 1

   Wiring and Connector Inspection: Check the wiring harness and connectors leading to both the crankshaft position sensor and the camshaft/pump position sensor. Look for open circuits, lost cables, or corrosion.

2. 2

   Sensor Mounting: Ensure the crankshaft position sensor is securely mounted and seated properly in the block.

3. 3

   Mechanical Timing Verification: If the sensors and wiring are intact, the issue may be mechanical. Check if the high-pressure fuel pump was recently replaced and incorrectly mounted.

4. 4

   Cam Gear Check: On some of these engines (like the 6.8L), the cam gears are not keyed and can slip on the camshaft. Cam timing may need to be checked using proper John Deere timing tools.

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Locate the Sensor

   Locate the crankshaft position sensor on the engine block (typically near the timing cover or flywheel housing, depending on the exact engine model).

3. 3

   Disconnect Wiring

   Carefully unplug the 2-pin electrical connector from the sensor.

4. 4

   Remove the Sensor

   Remove the retaining bolt holding the sensor in place and pull the sensor straight out of its bore.

5. 5

   Install the New Sensor

   Lubricate the O-ring on the new sensor with a small amount of clean engine oil. Insert it into the bore and tighten the retaining bolt to the manufacturer's torque specification.

6. 6

   Reconnect and Test

   Reconnect the electrical harness, reconnect the battery, and start the engine. Use a diagnostic tool (like John Deere Service ADVISOR) to clear the ECU 000637.07 code and verify that the engine RPM and sync data read correctly.