Case IH 19222 – Engine Control Module (ECM / ECU): Short circuit to ground on Blow By 3-way valve power stage output

The ECU detects that the power supply circuit to the Blow-By valve has shorted to ground. If the blow-by valve is configured to open when de-energized, a short circuit to ground prevents normal operation, and the ECU may be forced to open the main relay (ARly) to ensure the blow-by valve opens, which can affect engine performance or trigger secondary codes.

• Tier 4b
• Farmall 95U
• Farmall 105U
• Farmall 115U Pro
• Puma
• Maxxum
• Magnum
• Optum
• N-Series Loader Backhoes
• 580N

1. 1

   Inspect the wiring harness between the Engine ECU and the Blow-By 3-way valve for chafed insulation, pinched wires, or melted loom that could cause the power wire to touch ground.

2. 2

   Disconnect the plug at the Blow-By valve and the ECU to check for water intrusion, corrosion, or bent pins that could bridge the power circuit to a ground pin.

3. 3

   With the valve disconnected, use a multimeter to check for continuity between the power supply wire in the harness and a known chassis ground (wiring harness short cause).

4. 4

   Test the internal resistance of the Blow-By valve solenoid to see if the internal coil is shorted to its own metal housing (faulty valve cause).

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent ECU damage during electrical work.

2. 2

   Locate the Valve

   Locate the Blow-By 3-way valve. On FPT engines, it is typically mounted on or near the central tappet cover / valve cover.

3. 3

   Repair Wiring

   If the diagnostic tests revealed a short in the harness, splice and repair the damaged section of the wire using heat-shrink connectors, or replace the affected harness section.

4. 4

   Replace the Valve

   Disconnect the electrical connector and the vapor hoses attached to the 3-way valve. Remove the mounting hardware securing the valve to the engine and remove the old valve. Install the new Blow-By valve with a new gasket/O-ring (all gaskets must always be replaced in phase of assembly). Reattach the vapor hoses and tighten the mounting hardware.

5. 5

   Reassembly

   Reconnect the electrical connector to the valve. Reconnect the negative battery cable.

6. 6

   Clear Codes

   Connect the Case IH Electronic Service Tool (EST) or a compatible CAN-bus scanner to clear the inactive 19222 fault code from the ECU memory. Run the engine to verify the code does not return.