New Holland ATC 112 – ATC: Cab sensor shorted to ground

The voltage signal from the cab's interior temperature sensor has dropped below the minimum acceptable threshold, indicating a direct path to ground typically caused by a damaged wire touching the chassis, a crushed wiring harness, or an internal short within the sensor's thermistor.

• T6 Series
• T7 Series
• T8 Series
• T9 Series
• T6.140
• T7.210
• T8.410
• T9010
• Magnum (235-340 series)
• Puma
• Maxxum series

1. 1

   Locate the cab temperature sensor (in the return air duct or behind interior HVAC louver panels) and visually inspect the wiring harness for chafing, pinched wires, or melted insulation grounding against the cab frame

2. 2

   Perform a harness isolation test by disconnecting the sensor and checking for continuity between the signal wire and chassis ground (continuity indicates a shorted harness)

3. 3

   Measure the resistance across the pins of the disconnected sensor (a reading of zero or near zero ohms indicates an internal short in the sensor)

4. 4

   Inspect the pins at the ATC controller module for corrosion, moisture intrusion, or bent pins that could be bridging the sensor circuit to a ground pin

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Sensor

   Remove the interior cab trim panels or return air filter housing required to access the cab temperature sensor.

3. 3

   Removal

   Unplug the electrical connector from the sensor. Depending on the specific model, unclip or unthread the sensor from its mounting bracket in the air duct.

4. 4

   Installation

   Insert the new OEM cab temperature sensor into the mounting location and secure it.

5. 5

   Reconnection

   Plug the electrical harness back into the sensor, ensuring the locking tab clicks into place. Reinstall any removed cab trim panels.

6. 6

   Clear Codes

   Reconnect the battery and turn the ignition on. Use the tractor's onboard diagnostic display (e.g., AFS Pro / IntelliView monitor) or a diagnostic service tool to clear the ATC 112 fault code.

7. 7

   System Test

   Turn on the HVAC system and set it to "Auto." Verify that the system accurately reads the cabin temperature and adjusts the blower speed and A/C compressor clutch engagement accordingly.