Case IH 19092 – DCU (Dosing Control Unit): Monitoring VDD11 voltage - Dosing valve supply voltage high

This fault indicates that the 12-volt power supply circuit (VDD11) feeding the Diesel Exhaust Fluid (DEF) dosing module/valve is receiving a voltage that exceeds the maximum allowable threshold. This typically points to a short-to-power in the wiring harness or an internal failure within the dosing module or its controller.

• Tier 4a
• Case IH Magnum Series: 180, 200, 220, 235, 240, 250, 280, 310, 340, 380 (Series 4)
• Case IH Steiger / STX Series: 350 to 600 HP models
• Case IH Puma Series: 140, 150, 165, 185, 200, 210, 220, 240
• Case IH Maxxum Series
• Case IH Optum Series
• Case IH Farmall Series

1. 1

   Visually inspect the wiring harness running from the DCU to the DEF dosing module for chafing, melted insulation, or pinched wires that could cause a short to battery voltage (B+).

2. 2

   Disconnect the DEF dosing module and check the pins for corrosion, moisture intrusion, or bent terminals, which can bridge circuits and cause high voltage readings.

3. 3

   Using a multimeter, probe the VDD11 supply pin at the dosing module connector with the key on to verify if the voltage is actually exceeding the 12V upper limit.

4. 4

   Disconnect the harness at both the DCU and the dosing valve. Test the supply wire for continuity to power. If voltage is present on the wire while disconnected from the DCU, the harness is shorted.

1. 1

   Power Down

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

2. 2

   Isolate the Fault

   Based on the diagnostic checks, determine if the fault is in the wiring harness or the module itself.

3. 3

   Repair Wiring

   If a short-to-power is found in the harness, repair the damaged section of the wire or replace the affected harness segment.

4. 4

   Replace Dosing Module

   If the wiring tests perfectly but the DCU is outputting the correct voltage (meaning the dosing valve has an internal short causing the fault logic to trigger), replace the DEF dosing module. Disconnect the DEF fluid lines and electrical connector, unbolt the module from its mounting bracket/exhaust pipe, install the new module, and reconnect the fluid lines and electrical harness.

5. 5

   Reprogramming

   Program/calibrate the new DEF dosing module to the vehicle's DCU using the Case IH diagnostic tool (EST).

6. 6

   Clear Codes

   Use the universal controller or diagnostic tool to clear the stored 19092 / P0659 fault codes.

7. 7

   Test Run

   Run the engine and initiate a manual DEF dosing test to ensure the system pressurizes and the fault code does not return.