John Deere ECU001322.31 – ECU: Cylinder Misfire Detected with Engine Power Limitation

The Engine Control Unit (ECU) has detected a significant variation or lack of contribution from multiple cylinders, indicating an inefficiency in the combustion process (misfire). In response, the ECU logs this fault and derates the engine's power output to prevent potential damage, fuel wash of cylinder liners, or excessive emissions. The system suggests restarting the engine as a first step to attempt recovery.

• PowerTech 4.5L
• PowerTech 6.8L
• PowerTech 9.0L
• PowerTech 13.5L
• 9770 STS
• 9670 STS
• 1450CWS
• 1550WTS
• 9400 series
• 6000 series
• 7000 series
• 6615
• 6715
• 7220
• 7320
• 7420
• 7520
• 310SG
• 310J
• 710G
• 450J
• 700J
• 544J
• 200CLC

1. 1

   Check for other active or stored fault codes related to sensors, fuel pressure, or the EGR system, as these can cause misfires.

2. 2

   Inspect fuel level and quality, ensuring the fuel is not contaminated with water or debris.

3. 3

   Check and replace clogged or dirty primary and secondary fuel filters.

4. 4

   Visually inspect the engine wiring harness, especially sections connected to fuel injectors and large bulkhead connectors, for rubbing, corrosion, or loose connections.

5. 5

   Check the air intake system for a restricted air filter.

6. 6

   Perform a relative cylinder compression test using a diagnostic tool to check for mechanical issues (a deviation of more than 10% indicates a mechanical fault).

7. 7

   Monitor idle speed balance values using a diagnostic tool (for common rail systems) to identify the misfiring cylinder (e.g., a cylinder reading at the maximum limit like +100).

1. 1

   Isolate misfiring cylinder(s)

   If not identified electronically, carefully loosen the fuel line at each injector one at a time while the engine is idling. A cylinder causing little to no change in engine speed when its line is loosened is not firing correctly.

2. 2

   Replace fuel injector(s)

   Faulty fuel injectors are the most common cause. Replace the specific faulty injector, or replace all injectors if multiple are suspected or no other cause is found. Always replace associated seals and O-rings when replacing an injector.

3. 3

   Inspect high-pressure fuel lines

   Check the high-pressure fuel line leading to the suspect injector for any damage or leaks.

4. 4

   Address mechanical problems

   If compression tests indicate a mechanical problem, check valve lash for incorrect clearance, inspect the valve train (rocker arms, pushrods, valve springs) for damage, and perform an internal engine inspection for damaged pistons, rings, or cylinder liners.

5. 5

   Final verification

   After repairs are complete, clear all fault codes and run the engine under load to verify that the misfire is gone and the ECU 001322.31 code does not return.