Case IH 519048-04 - BCM – BCM: ATC inlet air temperature sensor - out of range - low

The signal voltage from the Automatic Temperature Control (ATC) inlet air temperature sensor has dropped below the normal operating range (less than 0.1 VDC). This usually points to a short to ground in the wiring circuit or a completely failed sensor whose internal resistance has dropped outside of permissible parameters.

• MAGNUM AFS Connect
• Steiger
• Magnum
• Optum AFS Series
• Puma AFS Series
• Farmall Series
• Axial-Flow Combines (7230, 8230, 9230)
• CNH Grape/Olive Harvesters
• WD2303

1. 1

   Inspect the wiring harness between the ATC inlet air temperature sensor and the Body Control Module (BCM) for chafed wires that may be causing a short circuit to ground.

2. 2

   Disconnect the sensor and inspect the pins for corrosion, moisture, or damage that could be bridging the connection and pulling the voltage down.

3. 3

   Use a multimeter to check the resistance of the temperature sensor. An out of range low voltage (under 0.1 VDC) often correlates to a sensor resistance reading as extremely hot (less than 50 ohms).

1. 1

   Locate the Sensor

   Locate the ATC inlet air temperature sensor, which is typically found in the cab's HVAC intake ducting or near the evaporator core.

2. 2

   Disconnect Power

   Turn off the machine's key switch and disconnect battery power to prevent any electrical spikes to the BCM.

3. 3

   Inspect and Test

   Disconnect the sensor's wiring harness. Test the harness side for a short to ground. If the wiring is good, the sensor itself has failed internally.

4. 4

   Replace the Sensor

   Remove the faulty inlet air temperature sensor and install the replacement part.

5. 5

   Reassemble and Clear Codes

   Reconnect the wiring harness, restore battery power, and turn the key switch to the RUN position. Use a diagnostic tool to clear the BCM fault codes and verify that the ATC system resumes normal operation without throwing the 519048-04 code.