Case IH 4300 – Transmission Controller (TRAX) or Electronic Hitch Remote (EHR) / Electronic Draft Control (EDC): Top link switch not fitted

This code indicates that the control module is programmed to expect a signal from the hydraulic top link control switch (typically located on the rear fender for adjusting the top link cylinder), but it cannot detect the switch on the network. This happens when the switch is physically missing, disconnected, has an open circuit, or if the tractor's software configuration is incorrectly set to expect a switch that the tractor was never equipped with.

• Puma/Mid Range Magnum
• Magnum series (e.g., 220, 235, 250, 315, 340, 380)
• Puma series
• Steiger models
• Case Construction 580ST
• Case Construction 590ST
• Case Construction 695ST

1. 1

   Verify Machine Configuration: Determine if the tractor is actually equipped with a hydraulic top link and rear fender switches.

2. 2

   Visual Inspection: If equipped, locate the top link switch on the rear fender. Inspect the switch for physical damage from debris or weather exposure.

3. 3

   Harness and Connector Check: Disconnect the switch and inspect the electrical connector for moisture, dirt, or corrosion. Check the wiring harness leading back to the EHR/Transmission controller for open circuits, chafing, or shorts to ground.

4. 4

   Check for Related Codes: Look for companion codes, such as 4301 (Side Link Switch Not Fitted), which usually indicates a shared harness issue or a broader configuration error.

1. 1

   Safely Park the Machine

   Park the tractor on a firm, level surface. Lower all attachments (hitch/loader) to the ground, shift the transmission into neutral, apply the parking brake, and turn off the engine.

2. 2

   Address Configuration Issues (If Not Equipped)

   If the tractor does not have a top link switch, a dealer technician must connect the Electronic Service Tool (EST) to the diagnostic port and reconfigure the Transmission/EDC controller settings to indicate that the top link switch is "Not Fitted." This will stop the module from looking for the switch.

3. 3

   Address Moisture/Corrosion (If Connector is Unused)

   If the wiring harness has a plug for the switch but the switch is not installed, ensure a blanking plug is installed. Moisture entering an open connector can cause CAN-bus or controller errors. Install a sealing plug to protect the circuit.

4. 4

   Replace the Switch (If Equipped and Faulty)

   Disconnect the wiring harness from the faulty fender switch. Unclip or unbolt the switch assembly from the fender housing. Install the new switch and securely reconnect the wiring harness.

5. 5

   Clear Codes and Test

   Turn the key on, clear the fault codes via the instrument cluster or EST, and test the fender buttons to ensure the hydraulic top link extends and retracts properly.