Case IH 519044-04 - BCM – BCM: ATC cabin air temperature sensor - out of range - low

The control module is receiving a voltage signal from the cabin air temperature sensor that is below the minimum acceptable threshold. This typically indicates a short to ground in the sensor's signal wire, a severely damaged wiring harness, or an internal short within the sensor itself.

• MAGNUM AFS Connect
• Magnum Series Tractors (MX series, AFS Connect models, 180, 200, 220, 240, 250, 310, 340, 380)
• Steiger / Quadtrac Series Tractors (STX series, 375, 425, 450, 470, 500)
• Puma Series Tractors (155, 160, 210)
• Axial-Flow Combines (7010, 7230, 8230, 8240, 9240)
• Patriot Sprayers (4420)
• CX Series Tractors (CX50, CX100)

1. 1

   Locate the Sensor: Find the cabin air temperature sensor (often referred to as the cab return air sensor). It is typically located in the overhead console, near the evaporator core, or in the cab's return air duct.

2. 2

   Inspect the Connector: Disconnect the 2-pin connector at the sensor. Check for pushed pins, moisture, or corrosion that could bridge the terminals and cause a short.

3. 3

   Check for Short to Ground: Using a digital multimeter, test the signal wire running from the sensor connector back to the BCM. Check for continuity to ground. If continuity exists, the wiring harness is chafed and shorting out against the chassis.

4. 4

   Test the Sensor: If the wiring harness tests good, the sensor has likely failed internally.

1. 1

   Turn off the machine's battery disconnect switch or turn the key to the OFF position to depower the BCM.

   Turn off the machine's battery disconnect switch or turn the key to the OFF position to depower the BCM.

2. 2

   Access the cabin air temperature sensor by removing the necessary interior trim panels or overhead console covers.

   Access the cabin air temperature sensor by removing the necessary interior trim panels or overhead console covers.

3. 3

   Unplug the 2-pin electrical harness from the sensor.

   Unplug the 2-pin electrical harness from the sensor.

4. 4

   Unclip or unthread the faulty sensor from its mounting bracket or HVAC housing.

   Unclip or unthread the faulty sensor from its mounting bracket or HVAC housing.

5. 5

   Install the new OEM temperature sensor.

   Install the new OEM temperature sensor.

6. 6

   Reconnect the 2-pin electrical harness, ensuring the locking tab clicks into place.

   Reconnect the 2-pin electrical harness, ensuring the locking tab clicks into place.

7. 7

   Reinstall all cab interior panels.

   Reinstall all cab interior panels.

8. 8

   Power on the machine and use the diagnostic display to clear the 519044-04 fault code from the BCM.

   Power on the machine and use the diagnostic display to clear the 519044-04 fault code from the BCM.

9. 9

   Run the ATC system to verify that the A/C and heater are properly regulating the cab temperature based on the setpoint.

   Run the ATC system to verify that the A/C and heater are properly regulating the cab temperature based on the setpoint.