Case IH 19221 – Engine Control Unit (ECU) / Vehicle Control Module (VCM): Short circuit to battery on Blow By 3-way valve power stage output

The engine's control module has detected that the voltage on the circuit controlling the blow-by (crankcase ventilation) 3-way valve is abnormally high, indicating that the control wire is shorted to a battery power source, or there is an internal short within the valve itself.

• Tier 4b
• Farmall 95U
• Farmall 105U
• Farmall 115U Pro
• Puma series
• 580N
• 580SN
• 590SN

1. 1

   Inspect the wiring harness between the ECU and the Blow By 3-way valve for chafing, melting, or pinched wires that could cause a short circuit to an external power source.

2. 2

   Disconnect the Blow By 3-way valve and inspect the electrical connectors at both the valve and the ECU for corrosion, moisture, or damaged pins.

3. 3

   Use a multimeter to test the control circuit wire for a short to battery voltage (with the key ON, engine OFF).

4. 4

   Test the internal resistance of the Blow By 3-way valve to determine if the short circuit is internal to the component.

1. 1

   Power down the machine, turn the key to the OFF position, and disconnect the negative battery cable.

   Power down the machine, turn the key to the OFF position, and disconnect the negative battery cable.

2. 2

   Locate the Blow By 3-way valve on the engine block/crankcase ventilation system and disconnect its electrical connector.

   Locate the Blow By 3-way valve on the engine block/crankcase ventilation system and disconnect its electrical connector.

3. 3

   Visually inspect the harness routing. If any wiring is rubbed through and touching a 12V power supply wire, repair the damaged section of the harness using OEM-approved wiring repair methods (solder and heat shrink).

   Visually inspect the harness routing. If any wiring is rubbed through and touching a 12V power supply wire, repair the damaged section of the harness using OEM-approved wiring repair methods (solder and heat shrink).

4. 4

   If the wiring harness tests good and shows no short to battery voltage when isolated, the short is internal to the Blow By 3-way valve's power stage.

   If the wiring harness tests good and shows no short to battery voltage when isolated, the short is internal to the Blow By 3-way valve's power stage.

5. 5

   Remove the mounting hardware securing the defective Blow By 3-way valve and remove it from the engine.

   Remove the mounting hardware securing the defective Blow By 3-way valve and remove it from the engine.

6. 6

   Install the new Blow By 3-way valve and torque the mounting hardware to OEM specifications.

   Install the new Blow By 3-way valve and torque the mounting hardware to OEM specifications.

7. 7

   Reconnect the electrical connector, ensuring the locking tab clicks into place.

   Reconnect the electrical connector, ensuring the locking tab clicks into place.

8. 8

   Reconnect the negative battery cable.

   Reconnect the negative battery cable.

9. 9

   Connect a diagnostic service tool, clear the inactive 19221 fault code, and run the engine to verify that the code does not return and the crankcase ventilation system operates normally.

   Connect a diagnostic service tool, clear the inactive 19221 fault code, and run the engine to verify that the code does not return and the crankcase ventilation system operates normally.