Case IH A-G-552 - Display – GNSS Receiver / Display Module: GNSS Position Jump

A 'GNSS Position Jump' indicates that the GPS/GNSS receiver has experienced a sudden, unexpected shift in its calculated physical location. This is typically caused by satellite bouncing, ionospheric map discrepancies, or signal obstruction/interference.

• MAGNUM AFS Connect
• STEIGER AFS Connect
• Case IH STX tractors
• Case IH sprayers

1. 1

   Check Satellite Settings: Navigate to the GPS/WAAS settings on the display. Check if the satellite selection is set to 'Auto'.

2. 2

   Monitor Signal Strength: Observe the Signal-to-Noise (SN) ratios for the WAAS satellites (e.g., 135 and 138). If they are equally strong, the system is likely switching between them at will.

3. 3

   Inspect Antenna Placement: Ensure the GPS antenna is not being blocked by part of the vehicle and is mounted at least 3 feet (0.9 m) away from any potential source of signal interference.

4. 4

   Startup Wait Time: Determine if the jump only happens immediately after startup. It can take up to five minutes for the SBAS map to fully download and stabilize the position.

1. 1

   Modify Satellite Selection

   To eliminate the potential for position jumps caused by satellite bouncing, change the receiver's setting to look for only one correction satellite at a time.

2. 2

   Lock the WAAS Satellite

   Pick the strongest WAAS satellite for your region, set it to 'ON,' and set the others to 'OFF'.

3. 3

   Update Firmware/Settings

   If using newer firmware (e.g., EZ-Guide version 1.0 or 3.0), you can utilize the 'Heed Health' setting, which allows the system to use the satellites for the position fix and improves the Dilution of Position (DOP) during times of low visibility.

4. 4

   Relocate Antenna

   If the issue is caused by physical obstruction, relocate the GPS dome/antenna to a higher, unobstructed point on the cab roof and recalibrate the steering system.