Case IH 15224 – Steering Valve Controller: Steering valve controller temperature too low

This fault is triggered when the steering valve controller measures a temperature of less than -40°C (-40°F). A reading of exactly -40°C almost universally indicates an open circuit (such as a disconnected sensor, broken wire, or completely failed thermistor) rather than an actual environmental temperature.

• Steiger T4B
• Farmall 40
• Farmall 45
• Farmall 50
• Farmall 115U Efficient Power

1. 1

   Inspect the wiring harness leading to the steering valve controller and its integrated/external temperature sensor for obvious signs of damage, chafing, or rodent damage.

2. 2

   Disconnect the steering valve controller temperature sensor connector. Check for pushed-back pins, corrosion, or moisture intrusion which could cause an open circuit.

3. 3

   Using a multimeter, check the resistance of the temperature sensor. An infinite resistance (OL) confirms the sensor has failed open.

4. 4

   If the sensor tests within normal resistance specifications, check the signal and ground wires between the sensor and the controller for continuity to rule out a broken wire.

1. 1

   Power down

   Power down the tractor and disconnect the battery.

2. 2

   Repair wiring

   If the diagnostic checks reveal a broken wire or damaged connector, repair the wiring harness using OEM-approved splicing methods or replace the pigtail connector.

3. 3

   Remove sensor

   If the temperature sensor itself has failed open (OL resistance), remove the faulty sensor from the steering valve assembly.

4. 4

   Install sensor

   Install the new temperature sensor and torque to OEM specifications. (If the sensor is internally integrated into the steering valve controller, the entire controller unit may require replacement).

5. 5

   Clear codes

   Reconnect the wiring harness, reconnect the battery, and clear the fault codes using a diagnostic scan tool.

6. 6

   Verify repair

   Cycle the steering system and verify that the controller is now reading a plausible temperature and that code 15224 does not return.