Case IH 2504 – UCM (Universal Control Module) or Transmission ECU: Clutch B solenoid – in use, an open circuit or short circuit to ground

This code indicates an electrical fault in the circuit controlling the transmission's Clutch B solenoid. The system has detected that while the solenoid is commanded to be in use, the circuit is either broken (open) or shorted directly to the ground.

• Optum
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225 CVX
• Maxxum MXM 120
• Maxxum 130
• Maxxum 140
• Maxxum 155
• Maxxum 175
• Maxxum 190

1. 1

   Inspect the wiring harness leading to the Clutch B solenoid (connector C027) for chafing, breaks, or melted insulation.

2. 2

   Disconnect the Clutch B solenoid and inspect the pins for corrosion, moisture, or poor terminal tension.

3. 3

   Measure the resistance between terminal 1 and terminal 2 directly on the Clutch B solenoid (specification is 8 to 11 Ohms).

4. 4

   Check the wiring harness for continuity from the solenoid connector back to the UCM/Transmission ECU, and test both wires for a short to ground.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery ground cable to prevent electrical spikes.

2. 2

   Locate the Solenoid

   Locate the transmission control valve block on the side of the transmission housing. Identify the Clutch B solenoid.

3. 3

   Replace the Solenoid

   If resistance was out of spec: Clean the area around the solenoid, disconnect the electrical connector, unbolt/unscrew the faulty Clutch B solenoid cartridge from the valve block, lubricate the O-rings on the new solenoid with clean transmission fluid (e.g., Case IH Akcela Nexplore), install the new solenoid, and torque to OEM specifications.

4. 4

   Repair Wiring

   If resistance was good but the harness failed: Splice and heat-shrink any broken wires, or replace the damaged section of the transmission harness.

5. 5

   Reassemble and Clear Codes

   Reconnect the electrical connector and the battery. Use the Case IH Electronic Service Tool (EST) or the tractor's H-Menu (diagnostic menu) to clear the stored 2504 fault code.

6. 6

   Test Operation

   Start the tractor and test the transmission through all gears/ranges to ensure normal operation and verify the code does not return. Note: A transmission clutch calibration may be required after replacing a clutch solenoid.