Case IH 116-04 - DEC – DEC: Service brake pressure sensor electrical circuit fault - voltage below normal

The control module is receiving a signal voltage from the sensor that has dropped below the minimum acceptable threshold (typically near 0 volts on a 5V reference circuit). This is usually caused by a short to ground in the sensor's signal wire, an open circuit or break in the 5V reference supply wire, an internally failed or shorted brake pressure sensor, or a faulty connection at the sensor harness.

• MAGNUM AFS Connect
• Puma series
• Puma 200
• Magnum
• Maxxum
• Farmall series
• Farmall 105U
• Farmall 75C
• AFX series
• AFX8010
• 7240
• 7250
• WD series windrowers

1. 1

   Monitor live data via the Universal Display 'DIAG' screen or Electronic Service Tool to check the live voltage reading of the service brake pressure sensor.

2. 2

   Disconnect the brake pressure sensor connector and visually inspect for water intrusion, dirt, or corroded/pushed-out pins.

3. 3

   With the key ON (engine off), measure the voltage at the 5V supply pin on the harness connector. If it reads 0V, trace the wire back to the DEC for an open circuit.

4. 4

   Verify continuity to ground on the ground pin, and check the signal wire for continuity back to the DEC, ensuring it is not shorted to chassis ground.

5. 5

   If the wiring tests perfectly, the sensor itself has failed internally and must be replaced.

1. 1

   Preparation

   Park the machine on a level surface, turn off the engine, and engage the parking brake. Depress the service brake pedal several times to relieve any residual hydraulic or pneumatic pressure in the brake lines.

2. 2

   Locate the Sensor

   Locate the service brake pressure sensor, which is typically threaded into the main brake valve block, the pneumatic trailer brake manifold, or the transmission housing depending on the specific model.

3. 3

   Disconnect Harness

   Unplug the electrical connector from the sensor.

4. 4

   Remove the Sensor

   Using a wrench, carefully unscrew the faulty pressure sensor from the port. Have a shop rag ready to catch any minor fluid drips if it is a hydraulic sensor.

5. 5

   Install the New Sensor

   Thread the new OEM pressure sensor into the port by hand to prevent cross-threading, then tighten to the manufacturer's specified torque.

6. 6

   Reconnect

   Plug the electrical harness back into the sensor, ensuring the locking tab clicks into place.

7. 7

   Clear Codes and Test

   Turn the key ON, clear the 116-04 fault code via the diagnostic display, and start the machine. Test the service brakes to ensure normal operation and verify that the fault code does not return.