Case IH 19039 – Engine Control Unit (ECU) / Aftertreatment Control Module: Exhaust gas temperature sensors signal drift at cold start only. Upstream oxidation catalyst temperature sensor comparison to a calculated temperature value failure.

The engine's control system has detected that the temperature reading from the upstream Diesel Oxidation Catalyst (DOC) exhaust gas temperature sensor is inaccurate. During a cold start, the sensor's reported temperature is drifting out of the expected range when compared to ambient air and engine coolant temperatures.

• Tier 4b
• Farmall 100C
• Farmall 105A
• Farmall 105C
• Farmall 105U
• Farmall 110A
• Farmall 110C
• Farmall 110U
• Farmall 115A
• Farmall 115C
• Farmall 115U
• Farmall 120U
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 140
• Puma 140
• Axial-Flow 5130
• Axial-Flow 5140
• Axial-Flow 7130
• Axial-Flow 7140
• Axial-Flow 7150
• Axial-Flow 7230
• Axial-Flow 7240
• Axial-Flow 7250
• Axial-Flow 9230

1. 1

   Perform a cold soak comparison by letting the machine sit overnight so the engine and exhaust system completely cool down to ambient temperature.

2. 2

   Connect a diagnostic scan tool and view live data for the Upstream DOC Exhaust Gas Temperature (EGT) sensor without starting the engine.

3. 3

   Compare the upstream EGT reading to the ambient air temperature and engine coolant temperature. They should be nearly identical; significant variance indicates sensor drift.

4. 4

   Inspect the 2-pin Bosch electrical connector and the wiring harness leading to the sensor for corrosion, melting, or chafing.

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical shorts. Ensure the exhaust system is completely cool.

2. 2

   Locate the Sensor

   Locate the upstream oxidation catalyst (DOC) temperature sensor on the exhaust aftertreatment assembly (usually the first sensor right after the turbocharger/exhaust manifold).

3. 3

   Disconnect

   Unplug the 2-pin electrical connector from the sensor.

4. 4

   Removal

   Using a 17mm wrench (or specialized sensor socket), carefully unscrew the sensor from the exhaust pipe. Note: Because of extreme heat cycling, these sensors often seize. Apply penetrating oil to the threads and let it sit if it does not break loose easily.

5. 5

   Installation

   Apply a small amount of high-temp anti-seize compound to the threads of the new sensor (ensure absolutely no anti-seize touches the sensor probe itself). Thread the new sensor into the exhaust pipe (M14x1.5 thread) and tighten to the manufacturer's torque specification.

6. 6

   Reassembly

   Reconnect the 2-pin electrical connector until it clicks. Reconnect the battery.

7. 7

   Clear Codes

   Turn the ignition on, connect your diagnostic tool, and clear the 19039 fault code. Start the engine and verify the code does not return.