New Holland 112 – ATC: Cab Temperature Sensor Shorted to Ground

The Automatic Temperature Control (ATC) module has detected a short to ground in the cab sensor circuit. This indicates that the sensor's signal wire is likely making direct contact with the vehicle's chassis or another ground path, causing the voltage reading to drop to near zero. This condition prevents the climate control system from accurately measuring the in-cab air temperature, which leads to improper heating and cooling performance.

• T8 Series
• T8.xxx
• T8010
• T8020
• T8030
• T8040
• T8050
• T7 Series
• T9000 Series
• New Holland CR Series Combines
• CR920
• CR940
• CR960
• CR970
• CR980

1. 1

   Visually inspect the cab temperature sensor and its wiring harness for physical damage, chafing, or corrosion. The sensor is typically a small grille or probe located within the cab's air return path to the HVAC unit.

2. 2

   Disconnect the sensor from the wiring harness and inspect the connector terminals for moisture, dirt, or damage.

3. 3

   Test the sensor resistance with a multimeter (with the sensor disconnected). A reading at or near zero Ohms indicates an internal short circuit within the sensor.

4. 4

   Test the wiring harness for a short to ground: with the sensor disconnected and the key OFF, measure continuity between the signal wire terminal in the harness connector and a known good chassis ground. A low resistance value or beep confirms a short in the harness.

1. 1

   Repair damaged wiring

   If visual inspection reveals chafed or damaged wires, repair the affected section using appropriate splicing and sealing techniques to protect it from moisture and vibration.

2. 2

   Clean connectors

   If the connectors are dirty or corroded, clean them with a suitable electrical contact cleaner and ensure a secure connection upon reassembly.

3. 3

   Address harness short

   If the wiring harness test confirms a short to ground, trace the harness to locate the point of failure (often caused by rubbing against the cab frame or chassis). Repair the damaged section and secure it to prevent future rubbing.

4. 4

   Replace the sensor

   If diagnostic tests point to an internal short within the cab temperature sensor itself (near zero Ohms resistance), replace the sensor.

5. 5

   Clear codes and verify

   After performing any repairs, clear the fault codes using a diagnostic tool and run the ATC system to verify that the fault does not return.