Case IH P31 – Electronic Management Unit (EMU): Steering Sensor Out Of Range - (Maximum Voltage)

This code indicates that the signal voltage from the front axle steering angle sensor has exceeded the maximum allowable threshold. This is typically caused by a short to +12V in the sensor wiring, a faulty connector, or an internal failure of the steering sensor itself.

• MXM
• MXM Series
• MXM 120
• MXM 130
• MXM 135
• MXM 140
• MXM 150
• MXM 155
• MXM 165
• MXM 175
• MXM 180
• MXM 190
• MXU Series
• Maxxum
• Puma
• Optum
• Magnum
• Steiger
• Vestrum
• Farmall A
• TM Series
• TM115
• TM190
• T6
• T7
• T8
• T6000
• T7000 Series
• CVT
• Profi Series

1. 1

   Check for a Short to +12 Volts: Disconnect the steering sensor connector (designated as C014). With the keystart turned ON, probe the red, yellow, and black wires of the harness to check for a short to +12V. If a short is found, trace the harness and repair the wires.

2. 2

   Test Sensor Resistance: Visually inspect the steering sensor. Check the resistance between the red and black wires at the sensor terminals. The resistance should measure between 5kΩ and 6kΩ. If the resistance is outside this range, the steering sensor is faulty and must be replaced.

3. 3

   Inspect Connectors: Inspect connector C014 for correct terminal installation, corrosion, or pushed-out pins. Reconnect C014 to see if the error code is still present.

4. 4

   Check EMU Harness: If the code persists, disconnect connector C014 and the EMU connector C105. Turn the keystart ON and check for short circuits on pins C105–28, C105–4, and related steering sensor circuits.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the steering angle sensor, which is mounted on the front axle kingpin assembly.

3. 3

   Disconnect and Remove

   Unplug the C014 electrical connector. Remove the mounting hardware securing the sensor to the axle housing.

4. 4

   Install New Sensor

   Mount the replacement steering sensor and secure the hardware.

5. 5

   Reconnect and Clear Codes

   Plug in the C014 connector. Reconnect the battery, turn the key ON, and use the tractor's H-Menu or a diagnostic tool to clear the P31 error code from the Electronic Management Unit.

6. 6

   Calibrate and Test

   Test the steering system for normal operation. Depending on the model, a steering angle calibration procedure may need to be performed via the tractor's configuration menu.