Case IH 19856 – Engine Control Unit (ECU): Physical Range Check high for turbine upstream temperature sensor

The Engine Control Unit has detected that the physical signal from the exhaust gas temperature sensor located just before the turbocharger (turbine upstream) is exceeding the maximum permissible limit. This typically indicates a short circuit to a voltage source (battery), an open circuit maxing out the voltage reading, or a sensor that has drifted and is reporting an impossibly high temperature.

• Tier 4b
• T7 Series tractors
• Skid Steer and Compact Track Loaders (SR130, SR160, SR175, SV185, SR210, TR270)
• Profi series tractors
• Magnum series tractors
• STM N Series Loaders

1. 1

   Visually inspect the turbine upstream temperature sensor (Exh_tTrbnUs) and wiring for physical damage, melting, or chafing.

2. 2

   Disconnect the sensor and inspect pins for corrosion, moisture, or poor tension.

3. 3

   Check the wiring harness back to the ECU for a short circuit to battery/voltage or an open circuit.

4. 4

   Perform a sensor plausibility test using a multimeter to check resistance (an open circuit or heavily drifted reading indicates internal failure).

1. 1

   Turn off the machine, remove the key, and allow the exhaust system and turbocharger to cool completely.

   This is necessary to avoid severe burns.

2. 2

   Disconnect the negative battery terminal.

   This prevents electrical spikes during the repair.

3. 3

   Disconnect the electrical connector from the turbine upstream temperature sensor.

4. 4

   Unthread the sensor from the exhaust manifold/turbine housing.

   Use the appropriate wrench or specialty sensor socket. Penetrating oil may be required if the sensor is seized from exhaust heat.

5. 5

   Apply a small amount of high-temp anti-seize to the threads of the new sensor.

   Ensure no anti-seize gets on the sensor probe itself.

6. 6

   Thread the new sensor into the housing and tighten to OEM torque specifications.

7. 7

   Reconnect the electrical harness.

   Ensure the locking tab clicks into place.

8. 8

   Reconnect the battery, turn the ignition on, and clear the inactive 19856 fault code.

   Use a CNH Electronic Service Tool (EST) or compatible diagnostic scanner.

9. 9

   Start the engine and monitor the live data for the turbine upstream temperature.

   Verify it is reading a plausible value and the code does not return.