New Holland ENG 3206 – Engine Control Unit (ECU): Cylinder6 Warning - Fast Decay Error

The fuel injector valve for cylinder 6 is staying open longer than intended. The engine controller monitors the output stages of the injectors and checks the function of the 'fast decay'. If the recovered switch-off energy is insufficient, the fast decay fails, meaning the injector solenoid cannot close fast enough after each injection. Engine power and speed will typically be heavily reduced (derated).

• T8.275
• T8.300
• T8.330
• T8.360
• T8.390
• T8.410
• T8.435
• T9 Series
• CR6090
• CR7090
• CR7.90
• CR8.90
• CR9.90
• CX8070
• CX8080
• CX8090
• Magnum Series (235-380)
• Steiger Series
• Axial-Flow Combines

1. 1

   Remove the engine valve cover to access the internal injector wiring harness.

2. 2

   Check the electrical connector specifically for the cylinder 6 injector. Ensure that the female pin in the injector wiring harness has a tight grip on the male pin of the injector, as vibration often causes this connection to loosen.

3. 3

   Verify the wiring from the ECU to the suspect injector is in good condition, checking for shorts or open circuits.

4. 4

   Remove the wiring from the cylinder 6 injector and use an ohmmeter to check the resistance of the injector solenoid. The resistance should be less than one (1) ohm and must not show an open circuit.

1. 1

   Secure the Connection

   If the diagnostic checks reveal a loose connection at the injector, reconnect it securely. To prevent the error from returning due to engine vibration, apply a high-temp silicone sealant around the male connector to stabilize it within the injector body.

2. 2

   Replace the Harness

   If the female pins in the harness are worn out or the wiring fails a continuity test, replace the under-cover injector wiring harness.

3. 3

   Replace the Injector

   If the wiring is good but the injector fails the resistance test (or if the code persists after securing the connections), the injector solenoid has failed internally. Replace the cylinder 6 fuel injector (and the injector sleeve if required by the cooling system design).

4. 4

   Reset Pre-load

   If the injector is replaced, you must reset the injector pre-load according to the exact specifications in your engine's service manual.

5. 5

   Clear Codes

   Reinstall the valve cover with a new gasket, clear the ECU fault codes, and test run the machine.