New Holland ATC 118 – ATC (Automatic Temperature Control): Outside air sensor shorted to ground

The signal voltage from the outside ambient air temperature sensor has dropped to near zero volts. The system interprets this as a direct short to ground, which prevents the automatic climate control system from accurately determining the outside temperature to regulate the cab climate.

• T6
• T7
• T8.xxx Series
• T9 Series
• T6000 Series
• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• CX Series
• CX8030
• CX8040
• CX8050
• CX8060
• CX8070
• CX8080
• CX8090
• FR Forage Cruisers
• Magnum 235–340 (Series 4)

1. 1

   Visually inspect the outside air sensor and wiring harness for chafed insulation, pinched wires, or rubbing against the metal chassis.

2. 2

   Unplug the sensor and inspect the electrical connector for moisture, dirt, or corrosion that could bridge the pins.

3. 3

   Perform a Sensor vs. Wiring Test: With the machine keyed on, disconnect the sensor. If the code changes to ATC 117, the sensor has failed internally. If it remains ATC 118, the short to ground is in the wiring harness.

1. 1

   Power Down

   Turn off the machine and remove the key. If repairing a damaged wiring harness, disconnect the battery.

2. 2

   Locate the Sensor

   Find the outside air temperature sensor. It is typically mounted in a shaded location outside the cab to prevent false readings from direct sunlight (often near the fresh air intake filter for the cab or behind the front grille).

3. 3

   Remove the Faulty Sensor

   Disconnect the electrical pigtail. Remove the sensor from its mounting bracket (some use a twist-off cover, while others are secured with a single screw or push-clip).

4. 4

   Repair Wiring (If Applicable)

   If the diagnostic test pointed to a harness short, trace the wire back to the ATC module, locate the chafed section, splice/solder the wire, and seal it with heat-shrink tubing.

5. 5

   Install the New Sensor

   Mount the replacement sensor into the bracket and securely plug in the electrical connector.

6. 6

   Clear Codes

   Turn the key on. Use the tractor's standard instrumentation display (TRANS VIEW / SET MENU) or the CNH Electronic Service Tool (EST) to clear the stored fault codes.

7. 7

   Verify Operation

   Check the cab display to ensure the outside ambient temperature is now reading accurately and the ATC system is functioning normally.