Case IH 3695 – Engine Control Unit (ENGINE ECU): Glow Plugs: Array of DFCs for Failure in Cylinder 1 Glow Plug

This code indicates that the engine control system has detected a failure, open load, or short circuit specifically isolated to the glow plug heating element or circuit for Cylinder 1.

• FPT F5C engines
• FPT F5H engines
• SR175 Skid Steer Loader
• SR250 Skid Steer Loader
• TR270 Compact Track Loader
• Farmall series tractors
• JX series tractors
• AVJ series tractors

1. 1

   Inspect the wiring harness leading to the Cylinder 1 glow plug for chafing, melting, or disconnected terminals.

2. 2

   Disconnect the electrical lead from the Cylinder 1 glow plug and measure resistance between the terminal and the engine block (ground). An open circuit (infinite resistance) or unusually high resistance confirms internal failure.

3. 3

   Turn the key to the 'ON' position (engine off) and verify that 12V is reaching the Cylinder 1 connector to rule out wiring harness or Glow Plug Control Unit issues.

1. 1

   Prep the Machine

   Park the machine on a level surface, turn off the engine, and disconnect the negative battery cable to prevent accidental shorts.

2. 2

   Locate Cylinder 1

   Identify Cylinder 1 on the engine block (typically the cylinder closest to the front of the engine/cooling fan).

3. 3

   Remove the Connector

   Carefully pull or unbolt the electrical connector/wire from the top of the Cylinder 1 glow plug.

4. 4

   Remove the Glow Plug

   Using a deep-well socket, carefully unthread the faulty glow plug from the cylinder head. Note: Apply penetrating oil beforehand and extract it slowly to avoid snapping the plug inside the cylinder head.

5. 5

   Install the New Part

   Thread the new OEM glow plug in by hand to prevent cross-threading, then tighten it to the manufacturer's specified torque rating.

6. 6

   Reassemble

   Reattach the electrical connector securely to the glow plug terminal.

7. 7

   Clear Codes

   Reconnect the battery. Use the Case IH Electronic Service Tool (EST) or a compatible diagnostic scanner to clear the 3695 fault code. Cycle the key and start the engine to ensure the code does not return.