New Holland NH 14061 – Central Controller / Machine Control Module (MCM): Air brake pressure short to VCC or option set but sensor not connected

The control module is detecting an abnormally high voltage on the air brake pressure sensor signal circuit (a short to the VCC/reference voltage). Alternatively, it means the tractor's software is configured ('option set') to expect an air brake pressure sensor, but the sensor is physically unplugged, missing, or the wiring is completely severed.

• T5.95
• T5.105
• T5.115
• T5.120
• T6 series (T6.120 to T6.180)
• T7 series (T7.170 to T7.270)
• T6000 series (T6010 to T6090)
• TS-A series
• Farmall U series
• Maxxum series
• Puma series

1. 1

   Verify Tractor Configuration: Determine if the tractor is actually equipped with pneumatic (air) trailer brakes. If not, the 'Air Brake' option needs to be disabled in the configuration menu using the dealer Electronic Service Tool (EST).

2. 2

   Visual Inspection: If equipped with air brakes, locate the air brake pressure sensor. Check the connector to ensure it is securely plugged in and not covered in dirt or corrosion.

3. 3

   Wiring Harness Check: Inspect the wiring harness leading to the sensor for chafing, pinched wires, or melted insulation that could cause the signal wire to short to the VCC (power) wire.

4. 4

   Voltage Test: Disconnect the sensor and use a multimeter to check the harness for proper 5V reference, ground, and signal return. If wiring tests good but the code is active, the sensor has failed internally.

1. 1

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

2. 2

   Locate the air brake pressure sensor on the pneumatic brake circuit lines.

3. 3

   Depress the locking tab and disconnect the wiring harness from the sensor.

4. 4

   If the wiring harness is damaged, repair the affected wires or replace the sensor harness pigtail.

   OEM # 87564372

5. 5

   If the sensor is faulty, use a wrench to unthread the old sensor from the pneumatic port.

   Note: Ensure all air pressure is bled from the system before removing the sensor.

6. 6

   Thread the new OEM Air Brake Pressure Sensor into the port and tighten to specification.

7. 7

   Reconnect the wiring harness until it clicks into place.

8. 8

   Reconnect the battery, turn the ignition on, and clear the stored fault codes. Run the tractor and test the air brakes to ensure the code does not return.