Case IH 19810 – Engine Control Module (ECM): Physical Range Check high for Charged Air cooler downstream temperature

This code indicates that the temperature reading from the sensor located downstream of the Charge Air Cooler (CAC / Intercooler) is registering a voltage or resistance value that translates to a temperature higher than the maximum allowed physical range. This typically points to a circuit issue (such as a short to power or an open circuit), a failed thermistor inside the sensor, or an actual extreme overheating condition in the charge air system.

• Tier 4b
• Tier 4 Final
• Puma
• Optum
• Magnum

1. 1

   Visually inspect the CAC downstream temperature sensor housing, connector, and wiring for physical damage, melting, or corrosion.

2. 2

   Using a multimeter, check the wiring harness between the sensor and the ECM for a short to battery/power or an open circuit.

3. 3

   Measure the resistance across the sensor pins and compare it to OEM specifications for the current ambient temperature to test the internal thermistor.

4. 4

   Use an infrared thermometer on the charge air cooler piping to verify the actual temperature. If genuinely overheating, inspect the charge air cooler fins for blockages and check turbocharger performance.

1. 1

   Preparation

   Turn off the machine, remove the key, and allow the engine and charge air cooler piping to cool completely to avoid burns.

2. 2

   Disconnect Power

   Disconnect the negative battery cable to prevent electrical spikes during the repair.

3. 3

   Remove the Sensor

   Disconnect the wiring harness connector from the CAC downstream temperature sensor. Carefully unscrew the sensor from the charge air piping or intake manifold.

4. 4

   Inspect the Port

   Check the mounting port for heavy soot or oil buildup, which could indicate a failing turbo seal or EGR issue. Clean the port threads if necessary.

5. 5

   Install the New Sensor

   Thread the new sensor into the port by hand to prevent cross-threading, then tighten to the OEM torque specification.

6. 6

   Reassembly

   Reconnect the electrical harness, ensuring the locking tab clicks into place. Reconnect the negative battery cable.

7. 7

   Clear Codes

   Connect the Case IH Electronic Service Tool (EST) or a compatible diagnostic scanner to clear the inactive 19810 fault code.

8. 8

   Test Run

   Start the engine and monitor the CAC downstream temperature live data to ensure it reads within normal operating parameters.