New Holland ENG 3989 – ENGINE ECU: Burner Injector 1 Error: High current

The engine control module has detected an abnormally high electrical current draw or a dead short on the circuit controlling the first burner injector.

• L213
• L216
• L220
• SR130
• SR160
• SR175
• Boomer 33
• Boomer 37
• Boomer 41
• Boomer 47
• Workmaster 33

1. 1

   Locate Burner Injector 1, which is mounted on the inlet side of the DOC/DPF (Diesel Oxidation Catalyst / Diesel Particulate Filter) assembly.

2. 2

   Inspect the wiring harness and connector (identified as connector Y-9021) for melted wires, chafing, or corrosion that could cause a short circuit.

3. 3

   Test the injector (Ohm Test): Disconnect the electrical connector from Burner Injector 1 and use a multimeter to check for continuity from pin 1 to pin 2. If the multimeter reads infinite resistance (open) or 0 Ω (dead short), the injector has failed internally.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Remove the Faulty Component

   If the multimeter test showed 0 Ω, the injector is shorted. Disconnect the fuel supply line to the burner injector (be prepared to catch residual fuel).

3. 3

   Extract the Injector

   Unbolt and remove Burner Injector 1 from the after-burner assembly.

4. 4

   Install the New Part

   Install the replacement burner injector. Reconnect the fuel line and torque to OEM specifications.

5. 5

   Address Wiring

   If the injector tested fine during diagnostics, the short is in the wiring harness between the Engine ECU and connector Y-9021. Locate the shorted wire, repair it using heat-shrink connectors, and re-loom the harness.

6. 6

   Reassemble and Clear Codes

   Reconnect the electrical connector (Y-9021) and the battery. Use a diagnostic scan tool to clear the ENG 3989 fault code.

7. 7

   Verify Repair

   Run the engine and initiate a stationary DPF regeneration to ensure the burner ignites properly and no high-current codes return.