Case IH 6912-18 - DEC – DEC: Transmission hydro motor speed sensor data valid but below normal operating range

The data from the transmission hydro motor speed sensor is valid but falling below the normal operating range (moderately severe). When this sensor fails or reads below normal, the tractor's computer receives inaccurate ground speed data, which can result in erratic shifting, failure to shift, complete loss of drive, or implement control issues.

• MAGNUM AFS Connect
• Magnum 180
• Magnum 200
• Magnum 220
• Magnum 225
• Magnum 240
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• Maxxum 115
• Maxxum 125
• Puma 165
• Optum 300 CVT
• MX series
• STX series
• Steiger
• 7010 Combine
• 7120 Combine
• 8010 Combine
• 8120 Combine
• 9010 Combine
• 9120 Combine
• AFX8010 Combine

1. 1

   Locate the sensor on the transmission and disconnect the electrical connector for visual inspection

2. 2

   Inspect the weather-sealed connector for moisture, dirt, or hydraulic fluid intrusion that could cause electrical resistance or signal loss

3. 3

   Verify that the sensor tip maintains the proper clearance and depth from the internal tone ring

1. 1

   Disconnect the old sensor's electrical connector.

2. 2

   Remove the mounting bolt securing the sensor to the transmission housing.

3. 3

   Remove the old sensor.

   Note: Some models feature an access cover for the hydro motor speed sensor that may need to be removed first.

4. 4

   Install the new direct-replacement sensor unit.

5. 5

   Ensure the sensor tip maintains proper clearance from the tone ring.

6. 6

   Reinstall the mounting bolt and reconnect the weather-sealed electrical connector.

7. 7

   Clear any active diagnostic codes from the tractor's computer.

8. 8

   Test operate the machine at various speeds to verify proper function and ensure the speedometer and transmission shifting are accurate.