Case IH A-G-100 - Display – Autoguidance System: No Communication with GNSS Receiver

This fault indicates that GNSS (Global Navigation Satellite System) receiver messages are not present on the CAN bus. The automatic steering and precision farming systems cannot be used because the display is unable to fix the current GPS position due to a total loss of communication with the receiver dome.

• MAGNUM AFS Connect
• STEIGER AFS Connect
• Magnum tractors
• Steiger tractors
• Puma tractors
• Axial-Flow combines
• Patriot sprayers

1. 1

   Cycle power to the machine and display to see if the receiver re-initializes on the CAN bus

2. 2

   Check vehicle fuses to ensure the GNSS receiver is receiving power

3. 3

   Inspect physical connections directly at the GNSS receiver dome on the cab roof

4. 4

   Check the integrity of the wiring harness between the receiver and the display/CAN bus for pinches, breaks, or corrosion

5. 5

   Ensure the receiver has a clear view of the sky and the adequate DGPS type is selected in the monitor

1. 1

   Power Down

   Turn off the tractor/combine and remove the key to ensure the CAN bus is asleep.

2. 2

   Fuse Replacement

   If the diagnostic checks revealed a blown autoguidance/GPS fuse, replace it with a fuse of the exact same amperage.

3. 3

   Harness Inspection & Repair

   Disconnect the main connector (Port A/B) at the back of the GNSS receiver. Inspect the pins for pushed-out terminals, moisture, or corrosion. Clean with electrical contact cleaner if necessary.

4. 4

   Voltage Test

   Using a multimeter, verify that the receiver is getting constant power and ground at the roof harness connector.

5. 5

   Component Replacement

   If the harness has power and ground but the A-G-100 code persists (meaning the CAN high/low communication has failed internally), the GNSS receiver itself has likely failed and must be replaced.

6. 6

   Re-initialization

   After replacing the receiver or harness, power on the AFS display. Drive the vehicle forward to allow the new GNSS receiver to initialize, determine its heading, and establish a fixed position.