New Holland ENG 3417 – Engine ECU: Short Circuit in Cylinder 4 Glow Plug

This code indicates that the engine controller has detected a short circuit in the electrical circuit specifically for the glow plug located in cylinder 4. This usually means the glow plug has failed internally and shorted to ground, or the wiring harness leading to that specific plug has rubbed through and is grounding out.

• L220
• L223
• L225
• L230
• L328
• SR175
• C227
• C232
• C238
• C337
• B90B
• B100B

1. 1

   Connect the Electronic Service Tool (EST) to clear the fault codes, then start and operate the machine to verify if the code returns or was a transient voltage issue.

2. 2

   Visually inspect the wiring harness and connectors leading to the cylinder 4 glow plug for chafed insulation, melted wires, or pinched harnesses that could cause a short to ground.

3. 3

   Disconnect the electrical connector from the cylinder 4 glow plug and use a multimeter to measure the resistance of the glow plug to ground. A reading of zero or near-zero ohms confirms the glow plug is internally shorted.

4. 4

   Inspect the Fast Glow Plug Control Unit (FGPCU) and the glow plug relays in the rear fuse box for signs of overheating or failure, as a dead short can sometimes damage the relay.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent electrical arcing.

2. 2

   Access the Glow Plug

   Locate cylinder 4 on the engine block and carefully disconnect the electrical plug/connector from the top of the pencil-type glow plug.

3. 3

   Remove the Faulty Plug

   Using an appropriate deep socket, carefully unscrew the faulty glow plug from the cylinder head. Note: Apply penetrating oil beforehand and extract it slowly to avoid snapping the glow plug inside the cylinder head.

4. 4

   Install the New Plug

   Thread the new glow plug into the cylinder head by hand to prevent cross-threading, then tighten it to the OEM specified torque.

5. 5

   Reconnect Wiring

   Reattach the electrical connector securely to the top of the new glow plug.

6. 6

   Reassemble and Test

   Reconnect the negative battery cable. Use the EST to clear the active fault codes. Start the engine and verify that the cold start system operates correctly and the code does not return.