Case IH 19145 – DCU (Dosing Control Unit): Dosing Valve (electrical) | short circuit to batt + | P2049 Reductant Injector - circuit high.

This code indicates that the electrical circuit controlling the Diesel Exhaust Fluid (DEF) dosing valve (also known as the reductant injector) has a short to battery positive (high voltage). The system is detecting higher voltage than expected on the control circuit, which prevents the valve from operating and dosing DEF into the exhaust stream properly.

• Tier 4a
• Tier 4b
• Case IH Magnum Series (180, 200, 220, 235, 240, 250, 280, 310, 340, 380)
• Case IH Steiger Series (350, 400, 450, 500, 550, 600)
• Case IH Puma Series (140, 150, 165, 185, 200, 220, 240)
• Case IH Maxxum Series
• Case IH Optum Series

1. 1

   Inspect the wiring harness running from the DCU to the DEF dosing valve for chafed wires, melted insulation from exhaust heat, or pinch points.

2. 2

   Disconnect the electrical connector at the DEF dosing valve and check for bent pins, corrosion, or DEF fluid intrusion.

3. 3

   With the key ON (engine off) and the valve unplugged, use a multimeter to probe the harness side of the connector for constant battery voltage on the control circuit.

4. 4

   Measure the internal resistance across the pins of the DEF dosing valve to check if the internal solenoid has failed or shows a dead short.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical spikes during the repair.

2. 2

   Wiring Repair (If Applicable)

   If the diagnostic checks revealed a short in the harness, repair the damaged section of wiring using heat-shrink butt connectors and re-loom the harness, ensuring it is routed safely away from the hot exhaust.

3. 3

   Remove the Dosing Valve

   If the valve itself is internally shorted, clean the area around the DEF doser on the exhaust pipe to prevent dirt from entering the SCR system.

4. 4

   Disconnect Lines

   Carefully disconnect the DEF fluid supply line from the dosing valve (be prepared for minor fluid spillage) and unplug the electrical connector.

5. 5

   Unbolt the Valve

   Remove the mounting bolts/clamp securing the dosing valve to the exhaust system and remove the unit.

6. 6

   Install the New Valve

   Install the replacement DEF dosing valve. Torque the mounting hardware to OEM specifications to ensure an exhaust-tight seal.

7. 7

   Reconnect

   Reattach the DEF supply line and plug in the electrical connector.

8. 8

   Clear Codes and Test

   Reconnect the battery. Use a diagnostic scan tool to clear the 19145 / P2049 fault codes from the DCU. Perform a forced DEF dosing test via the diagnostic tool, or run the machine up to operating temperature to verify that the code does not return and that there are no DEF leaks at the fitting.