New Holland 3416 – ECM: Short Circuit in Glow Plug 4

The Engine Control Module (ECM) has detected a short circuit in the electrical circuit for the glow plug in cylinder number 4. A short circuit indicates that electrical current is diverting from its intended path, which can cause the glow plug to either not heat up at all or overheat, potentially damaging the plug. This condition may prevent the engine from starting properly, especially in cold weather, and can cause irregular operation such as rough idling after startup and excessive white smoke from the exhaust.

• T-series
• T6
• T7
• Boomer
• Boomer 3040
• Boomer 3045
• Boomer 3050
• TC
• TC-series
• TC25
• TC35
• T2310
• T1510
• T2210
• 1215
• 1320
• 1920
• 2120
• L-series
• L125
• L160
• LS-series
• LS160
• LS170
• C-series
• SR175
• SV185
• LB620

1. 1

   Visually inspect the glow plug and its wiring harness at cylinder 4 for any signs of damage, corrosion, or loose connections.

2. 2

   Disconnect the electrical connector from the top of the glow plug in cylinder 4 to isolate it for accurate testing.

3. 3

   Perform a resistance test on the glow plug using a multimeter set to Ohms (Ω). Place one probe on the top terminal and the other on a clean engine block ground. A good plug typically reads between 0.5 and 2.0 ohms (e.g., 1.0 ohm +/- 0.1 ohm for LS160/LS170). A reading of 0 ohms confirms a short circuit in the plug. A very high resistance reading (often displayed as 'OL' or '1') indicates an open circuit (a broken internal filament), which is a different failure mode but still requires plug replacement.

4. 4

   If the glow plug tests good, inspect the wiring harness leading to it for chafing, breaks, or areas where it might be contacting the engine block or other metal components (indicating a harness short).

1. 1

   Safety First

   Ensure the engine is cool and disconnect the negative battery terminal to prevent any accidental electrical shorts.

2. 2

   Remove the Electrical Connector

   Disconnect the wire from the top of the failed glow plug.

3. 3

   Loosen the Glow Plug

   If the engine uses a bus bar to connect the glow plugs, you will need to remove the nuts and the bar to access the individual plug. Apply a penetrating oil around the base of the glow plug and let it soak to help loosen it and prevent it from breaking off in the cylinder head.

4. 4

   Remove the Old Glow Plug

   Using the correct size deep socket, carefully turn the glow plug counter-clockwise to remove it.

5. 5

   Clean the Threads

   It is good practice to clean the threads in the cylinder head with a thread chaser to ensure the new plug seats correctly.

6. 6

   Install the New Glow Plug

   Apply a small amount of anti-seize compound to the threads of the new glow plug. Thread it in by hand to avoid cross-threading, then tighten it to the manufacturer's specified torque, which is typically around 12-15 ft-lbs. Do not overtighten.

7. 7

   Reconnect and Finalize

   Re-install the bus bar if equipped, and reconnect the electrical wire to the new glow plug. Apply dielectric grease to the terminal to prevent corrosion. Reconnect the negative battery terminal.

8. 8

   Clear Fault Codes

   After the repair, use a diagnostic tool to clear the fault code from the ECM and start the engine to verify the repair.