Case IH 19452 – Engine Control Module (ECM): Fault Check for enhanced SRC-Min of fifth exhaust gas temperature

This code indicates a Signal Range Check - Minimum (SRC-Min) failure for the 5th Exhaust Gas Temperature (EGT) sensor. The control module has detected that the temperature reading from this specific sensor in the aftertreatment system is falling below the physically plausible minimum limit for the current engine operating conditions. This typically points to a failed sensor, a wiring issue (such as an open circuit or high resistance causing a falsely low reading), or an exhaust leak upstream of the sensor preventing hot exhaust gases from reaching it.

• Tier 4b
• Maxxum series (115, 125, 145, 150)
• Puma series
• Optum
• Farmall series (100C, 105A/C/U, 110A/C/U, 115A/C/U, 120U)
• Quantum
• Vestrum series
• Case N-series Tractor Loader Backhoes (TLBs)

1. 1

   Inspect the exhaust system for any obvious exhaust leaks upstream of the 5th EGT sensor (usually located near the DPF or SCR unit).

2. 2

   Inspect the wiring harness leading to the sensor for chafed wires, melted insulation, or a disconnected plug.

3. 3

   Disconnect the 2-pin connector and check for corrosion, moisture, or bent pins.

4. 4

   Connect a diagnostic scan tool and monitor live data for the 5th EGT sensor. If it reads a static, implausibly low value (e.g., -40°C), there is an open circuit or internal failure. If it fluctuates erratically, suspect a loose connection or failing sensor element.

5. 5

   Test the sensor's resistance with a multimeter and compare it to the OEM specification chart for the ambient temperature. An open reading (infinite resistance) confirms a dead sensor.

1. 1

   Cool Down

   Ensure the engine is turned off and the exhaust system has completely cooled down. Exhaust components operate at extreme temperatures and pose a severe burn risk.

2. 2

   Locate the Sensor

   Identify the 5th EGT sensor on the aftertreatment exhaust piping.

3. 3

   Disconnect

   Carefully unplug the 2-pin electrical connector from the sensor harness.

4. 4

   Remove the Sensor

   Using an appropriately sized wrench (often 17mm for M14x1.5 threaded sensors), loosen and remove the faulty EGT sensor from the exhaust pipe.

5. 5

   Prepare the New Sensor

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor (if it does not already come pre-coated from the factory). Note: Do not get anti-seize on the sensor probe itself.

6. 6

   Install

   Thread the new sensor into the exhaust pipe by hand to prevent cross-threading, then tighten it securely with a wrench.

7. 7

   Reconnect

   Plug the electrical connector back into the machine's wiring harness, ensuring it clicks into place. Secure any loose wire routing with zip ties if necessary to keep it away from direct heat sources.

8. 8

   Clear Codes

   Turn the key on, connect your diagnostic tool, and clear the 19452 fault code. Start the engine and verify that the live temperature reading is now plausible and rising as the exhaust warms up.