Case IH 299023-19 - VCM – VCM: Steering valve coil supply switch disagreement

This code indicates an electrical mismatch in the automated steering control circuit. The control module detects that the commanded state of the steering valve coil's power supply switch does not match the actual electrical feedback (current draw or voltage) from the steering valve coil circuit. This typically points to an open circuit, a short circuit, a failed solenoid coil, or a faulty supply switch/relay failing to provide the expected power.

• MAGNUM AFS Connect
• Case IH Magnum Series (e.g., 240, 280, 340)
• Case IH Steiger / Quadtrac Series
• Case IH Puma and Maxxum Series

1. 1

   Clear the fault code on the AFS display, cycle the key, and see if the code returns immediately upon steering activation to rule out intermittent hardware over-current detection.

2. 2

   Inspect the wiring harness between the UCM/VCM and the steering control valve for chafed wires, pinched harnesses, or corrosion inside the electrical connectors.

3. 3

   Disconnect the steering valve coil and measure its resistance (Ohms) with a multimeter to determine if the coil is internally shorted or open.

4. 4

   Back-probe the supply switch/relay circuit to verify that the UCM is actually sending the correct voltage to the coil when automated steering is engaged.

1. 1

   Disconnect power

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

2. 2

   Access the steering valve

   Locate the priority/steering control valve block (typically located under the cab or near the front axle hydraulics, depending on the tractor model).

3. 3

   Replace steering valve coil

   If the coil failed the resistance test (coil failure cause): Remove the retaining nut on the end of the steering solenoid valve, slide the old coil off the cartridge, and install the new coil.

4. 4

   Repair wiring harness

   If the wiring is damaged (wiring fault cause): Repair the broken wire using weather-sealed splice connectors or replace the damaged harness section.

5. 5

   Replace supply switch

   If the supply switch/sensor is faulty (switch failure cause): Unthread the faulty switch from the hydraulic block and install the new switch, ensuring the O-ring is properly seated.

6. 6

   Reassemble and reconnect

   Plug the electrical connectors back in, ensuring the locking tabs click into place. Reconnect the battery.

7. 7

   Calibrate and test

   Turn the key on, clear any stored UCM/VCM fault codes from the display, and perform a steering system test or automated steering calibration to verify the System Ready status is achieved.