Case IH Tractor ATC 116 Fault Code Guide

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What ATC 116 Means

ATC 116 is a Case IH tractor climate control fault code from the ATC controller. The official description is: Evaporator sensor shorted to ground.

In practical terms, the ATC controller is detecting an electrical condition in the evaporator sensor circuit that looks like the signal is being pulled to ground. This does not automatically prove the sensor itself has failed, but it does mean the evaporator sensor circuit needs diagnosis.

Likely Symptoms

Depending on the tractor and climate control system behavior, possible symptoms may include:

  • Air conditioning performance may be reduced or inconsistent.
  • The climate control system may not regulate temperature normally.
  • The A/C system may cycle differently than expected.
  • The fault code may return after being cleared.
  • There may be no obvious operator symptom other than the stored fault code.

Possible Causes

Because the official fault points to a short-to-ground condition, possible causes include:

  • A failed evaporator temperature sensor.
  • Damaged wiring insulation in the evaporator sensor circuit.
  • A pinched, rubbed, or grounded harness.
  • Moisture, corrosion, or contamination in a connector.
  • Loose, damaged, or backed-out connector terminals.
  • An ATC controller input issue, though wiring and sensor checks should normally be considered first.

Diagnostic Checks

Confirm the Fault

  • Record the fault code before clearing anything.
  • Check whether ATC 116 is active or stored, if the display or diagnostic tool provides that information.
  • If the code is cleared, operate the climate control system and see whether the fault returns.

Inspect the Circuit

  • Inspect accessible wiring and connectors related to the evaporator sensor circuit.
  • Look for rubbed-through insulation, pinched wiring, corrosion, moisture, or loose terminals.
  • Check that connectors are fully seated and not damaged.

Test According to Service Information

  • Use the Case IH service information for the correct connector views, circuit identification, and test method.
  • Check the evaporator sensor circuit for an unintended path to ground.
  • Test the sensor only using the procedure and specifications for the machine being serviced.
  • Avoid applying power, jumping terminals, or probing connectors in a way that could damage the ATC controller.

Repair Guidance

Repairs should be based on test results, not the code alone. Common corrective actions may include:

  • Repairing damaged wiring or harness protection.
  • Cleaning, drying, or repairing affected connectors.
  • Correcting loose or damaged terminals.
  • Replacing the evaporator sensor if testing confirms it is faulty.
  • Further ATC controller diagnosis if the sensor and wiring test correctly but the fault remains.

After repairs, clear the fault code if the system allows, operate the climate control system, and confirm that ATC 116 does not return.

When Dealer Tools or a Technician May Be Required

Dealer diagnostic equipment or a qualified technician may be required if the fault cannot be confirmed with basic checks, if live ATC data is needed, if connector and circuit identification is unclear, or if controller-level diagnosis is suspected. Professional diagnosis is also recommended when the fault returns after wiring and sensor checks have been completed.

Contact a Nearby Case IH Service Center

Bottom Line

Case IH tractor fault code ATC 116 means the ATC controller has detected the evaporator sensor shorted to ground. Start with careful inspection of the sensor circuit and connectors, then follow the service manual test procedure before replacing parts.

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