Case IH 16117 – ATC (Automatic Temperature Controller): Outside Air Temperature Sensor is open or shorted to power

The control module is receiving a voltage signal from the sensor circuit that is higher than the expected operating range. This happens when there is a physical break in the wire (an open circuit), a disconnected plug, an internal failure of the sensor itself, or the sensor's signal wire is chafing and shorting against a positive power source.

• Puma/Mid Range Magnum
• Maxxum
• Case IH Magnum Series
• Case IH Puma Series
• Case IH Steiger Series

1. 1

   Visually inspect the outside air temperature sensor and wiring harness for pinched wires, chafing, or rodent damage.

2. 2

   Disconnect the sensor and inspect the connector pins for pushed-back pins, corrosion, or moisture.

3. 3

   Perform a resistance test across the sensor's terminals using a multimeter (infinite resistance/OL indicates an internal open circuit and a dead sensor).

4. 4

   Perform a voltage check at the harness-side connector with the key ON (should see a 5V reference; 12V indicates a short to power).

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery terminal to prevent any accidental electrical spikes while working on the ATC system.

2. 2

   Access the Sensor

   Remove any cab cowls, covers, or intake grilles necessary to access the outside air temperature sensor.

3. 3

   Remove the Faulty Sensor

   Unplug the electrical connector. Unclip or unthread the sensor from its mounting bracket.

4. 4

   Harness Repair (If Applicable)

   If your diagnostic checks revealed a broken or shorted wire, splice and heat-shrink the damaged section of the harness.

5. 5

   Install the New Sensor

   Snap or thread the new temperature sensor into the factory mounting location. Reconnect the electrical harness, ensuring the weather-pack seal clicks firmly into place.

6. 6

   Reassemble and Clear Codes

   Reinstall any removed panels. Reconnect the battery. Turn the ignition on and use the AFS Pro monitor or diagnostic tool to clear the inactive 16117 / ATC 117 fault code.

7. 7

   Verify Operation

   Run the tractor's HVAC system on "Auto" to ensure the climate control regulates properly and the code does not return.