Case IH 2881 – CCM2 or TCU / UCM: Park Brake Pressure Transducer Open Circuit or Shorted to Ground

This fault indicates an electrical failure in the circuit of the Park Brake Pressure Transducer (Sensor). It can be caused by an open circuit (break in wiring, disconnected plug, or failed internal resistor) or a short to ground (signal wire chafed touching chassis, or internal short). Because of this, the controller cannot verify if the park brake is safely released, which will typically trigger a warning lamp and may inhibit machine movement or transmission shifting.

• Steiger T4B
• AFX8010
• 7010
• 8250
• 9120
• Steiger 350
• Steiger 400
• Steiger 450
• Steiger 500
• Steiger 550
• Steiger 600
• Quadtrac 350
• Quadtrac 400
• Quadtrac 450
• Quadtrac 500
• Quadtrac 550
• Quadtrac 600
• Magnum
• Maxxum
• 586H

1. 1

   Locate the Sensor: It is typically located on the right side of the transmission housing or directly on the brake control valve manifold.

2. 2

   Check the 5V Reference: Disconnect the sensor. Turn the key ON. Using a multimeter, verify that a 5V power supply is reaching the sensor from the controller.

3. 3

   Check the Signal Wire: Test the signal return wire back to the controller for continuity.

4. 4

   Check for Shorts: Test the signal wire for continuity to the chassis ground. If there is continuity, the wiring harness is rubbed through and shorting out.

5. 5

   Inspect Connectors: Look for pushed-out pins, corrosion, or moisture inside the sensor connector.

1. 1

   Relieve Pressure

   Ensure the machine is parked on level ground, the engine is off, and the wheels/tracks are chocked. Relieve hydraulic system pressure according to the operator's manual.

2. 2

   Disconnect Wiring

   Unplug the electrical connector from the Park Brake Pressure Transducer.

3. 3

   Remove the Sensor

   Using the appropriate wrench (often a stubby wrench is required due to tight clearances near the valve body), unscrew the sensor from the manifold. Have a rag ready to catch minor hydraulic fluid drips.

4. 4

   Install the New Sensor

   Thread the new OEM pressure transducer into the port. Tighten to the specified torque (do not over-tighten as it can damage the manifold threads).

5. 5

   Reconnect and Clear

   Plug the electrical connector back in. Turn the battery disconnect back on, power up the machine, and use the Universal Display or a diagnostic tool to clear the inactive fault codes.

6. 6

   Test Operation

   Start the machine and cycle the park brake switch. Verify that the park brake warning light turns off when released and that the machine moves without hesitation.