Case IH 5949-05 - VCM – VCM: VCM: Oil cooler bypass solenoid current low

The control module is detecting less electrical current than expected on the circuit that operates the oil cooler bypass solenoid. This typically points to an open circuit, high resistance, a disconnected wiring harness, or a failed (internally open) solenoid coil.

• MAGNUM AFS Connect
• Case IH Magnum series

1. 1

   Visual Inspection: Locate the oil cooler bypass solenoid (often located near the rear axle or transmission cooling block). Check the 2-pole electrical connector (designated as connector X-377 in some CNH diagrams) for disconnection, corrosion, or pushed-out pins.

2. 2

   Wiring Harness Test: Check the wiring harness between the VCM and the solenoid for chafing, breaks, or an open circuit.

3. 3

   Solenoid Coil Test: Use a multimeter to measure the resistance across the two pins of the oil cooler bypass solenoid. If the reading is 'OL' (Open Loop) or shows excessively high resistance, the solenoid coil has failed internally.

1. 1

   Power Down

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

2. 2

   Access the Solenoid

   Locate the oil cooler bypass solenoid on the hydraulic/cooling block.

3. 3

   Repair Wiring/Connector

   If the diagnostic checks revealed a broken wire or a melted/corroded connector, splice in a new connector pigtail. Heat-shrink all connections to prevent moisture ingress.

4. 4

   Replace Solenoid (if faulty)

   If the solenoid coil tested open, unthread the retaining nut holding the solenoid coil to the valve stem, slide the old coil off, and install the new replacement coil. (If the entire cartridge valve is damaged, unthread the cartridge from the block and install a new one, ensuring O-rings are lubricated).

5. 5

   Reassembly & Testing

   Reconnect the wiring harness and the battery. Start the tractor, allow it to reach operating temperature, and use a diagnostic tool to clear the VCM fault codes. Verify the code does not return.