Case IH F-GNSS-400 - Display – Guidance and GNSS system: No Serial Communication with GNSS Receiver

This fault indicates that GNSS receiver messages are not present on the selected serial port. The display is failing to receive the required NMEA data strings (specifically the GGA message) from the GNSS receiver at the expected baud rate.

• MAGNUM AFS Connect
• STEIGER AFS Connect
• Magnum™ and Steiger® series tractors
• Long-wheelbase Puma® and Optum® series tractors
• Axial-Flow 260 and AF series combines
• Patriot® 50 series sprayers

1. 1

   Verify Port Settings: Check the receiver's serial port settings and message configuration. The baud rate must be set to 19,200.

2. 2

   Verify NMEA Messages: Ensure that the GGA message is enabled in the receiver's output settings.

3. 3

   Physical Connection Check: Inspect the serial/data cable connecting the GNSS receiver to the display (e.g., 9-pin serial, Deutsch, or 12-pin Conxall connectors) for loose connections, bent pins, or corrosion.

4. 4

   Power Check: Verify the GNSS receiver is receiving power and that the LED status indicator on the receiver is illuminating.

1. 1

   Access Receiver Configuration

   Use the display interface or connect the GNSS receiver to an office computer using a power/data cable (e.g., P/N 50166S) and the AgRemote utility.

2. 2

   Adjust Baud Rate

   Navigate to the Port Configuration settings (e.g., Port A or Port B depending on your wiring) and change the baud rate to 19,200.

3. 3

   Enable NMEA Strings

   Navigate to the NMEA settings screen. Ensure that the GGA message is toggled to "enabled" (often indicated by uppercase letters in the AgRemote utility). Standard setups may also require GSA, VTG, and RMC to be enabled.

4. 4

   Save and Reboot

   Save the configuration changes, disconnect from the PC (if applicable), and reboot the tractor/display.

5. 5

   Harness Testing

   If the settings are correct but the code persists, use a multimeter to test the serial communication lines between the receiver roof harness and the back of the Pro 1200 display for continuity.

6. 6

   Hardware Replacement

   If the harness has continuity but no data is being transmitted (verified via a functional test on AgRemote), the GNSS receiver's internal serial port has failed and the receiver must be replaced. If the harness is broken, replace the specific adapter or main harness.