Case IH 19531 – Engine Control Module (ECM) / Engine Control Unit (ECU): Misfire detected in cylinder 6

The system has detected a power contribution imbalance or a lack of combustion in cylinder 6 (or cylinder 2 on 4-cylinder engines). This is typically caused by a lack of fuel, a faulty injector, aerated fuel, or a mechanical base-engine issue (such as damaged cams or lifters).

• Tier 4b
• Magnum Series: 180, 190, 200, 225, 240
• Puma Series: 130, 140, 145, 155, 160, 170, 185, 200, 205, 215, 225, 230
• Maxxum Series: 110, 120, 130
• Combines: AF4130, AF5130
• Wheel Loaders / Construction: 621F, 721F, 821E, 821F, 921F, 865B, 885B
• Patriot Sprayers

1. 1

   Use an electronic service tool to perform a Fuel Correction Test / Cylinder Balance Test to verify that cylinder 6 is the underperforming cylinder

2. 2

   Check the low-pressure fuel supply for restrictions or aeration (air in the fuel lines)

3. 3

   Check the cylinder 6 fuel injector hold-down torque and inspect for a leaking combustion chamber gasket

4. 4

   Inspect the wiring harness and connectors leading to the cylinder 6 injector for shorts, opens, or corrosion

5. 5

   If fuel and electrical systems pass, perform a compression test or inspect the valvetrain for damaged cams and/or lifters

1. 1

   Isolate the Fault

   Confirm the misfire is isolated to cylinder 6 using the diagnostic scan tool.

2. 2

   Inspect Wiring

   Disconnect the cylinder 6 injector harness and check for damage. Repair the harness if necessary.

3. 3

   Replace the Injector

   If the wiring is intact and fuel supply is clean/unaerated, the injector is likely defective. Remove the high-pressure fuel line and injector hold-down clamp for cylinder 6.

4. 4

   Install New Injector

   Install the replacement injector with a new nozzle washer and O-ring seal. Torque the hold-down bolt and high-pressure lines to OEM specifications.

5. 5

   Reassemble and Bleed

   Reconnect the electrical harness, bleed the fuel system if required by the service manual, and clear the fault codes from the ECM.

6. 6

   Test Run

   Run the engine and perform another cylinder balance test to verify the misfire is resolved.