New Holland 15512 – Electronic Management Unit or Steering Controller: Primary Steering Pressure Sensor Under Voltage

The control module has detected that the voltage signal from the primary steering pressure sensor is below the normal operating range. This under-voltage condition typically indicates a short to ground in the wiring circuit, a faulty pressure sensor, or an issue with the control module itself.

• T6 Series
• T7 Series
• T7.170
• T7.315
• T8 Series
• T9 Series

1. 1

   Check hydraulic fluid level and quality to ensure it is within the recommended range and not contaminated.

2. 2

   Visually inspect the wiring harness and electrical connector for the primary steering pressure sensor for damage, corrosion, dirt, or loose pins. Ensure the connector is securely fastened.

3. 3

   Check for a short to ground: Disconnect the sensor, turn ignition ON, and measure voltage between the signal wire pin in the harness connector and chassis ground.

4. 4

   Measure conductivity between the signal pin and the ground pin in the harness connector to verify if a short exists. If a short is indicated, the wiring harness must be repaired or replaced.

5. 5

   Test the sensor resistance: With the sensor disconnected, measure resistance between pin 1 and pin 3 of the sensor. Expected resistance is 5-6K Ohms. If outside this range, the sensor is faulty.

6. 6

   If the harness and sensor test correctly, have a qualified technician check the Steering Controller (Electronic Management Unit) pins and connections.

1. 1

   Locate and clean sensor area

   Locate the primary steering pressure sensor (typically near the main steering hydraulic valve block or steering pump; on T7 models, right side near battery and main hydraulic filter). Thoroughly clean the surrounding area to prevent contamination.

2. 2

   Remove the faulty sensor

   Disconnect the electrical connector, place a drain pan underneath to catch fluid, and carefully unscrew the sensor using an appropriate wrench.

3. 3

   Install the new sensor

   Ensure threads and port are clean. Install the new O-ring or sealing washer, screw the new sensor into the port, and tighten to the manufacturer's specified torque. Do not overtighten.

4. 4

   Bleed system and verify operation

   Reconnect the electrical connector, start the tractor, and check for leaks. Turn the steering wheel from lock to lock several times to bleed air from the system.

5. 5

   Clear fault code

   Clear the fault code from the control module using a diagnostic tool or the operator's manual procedure.