Case IH 520202-06 - PCM – PCM: GNSS antenna short circuit to ground

The voltage supply or signal wire to the Global Navigation Satellite System (GNSS) antenna has shorted directly to a ground source, preventing the module from receiving satellite positioning data.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect series
• Case IH Steiger / Quadtrac T4B CVT series
• Case IH Patriot High-Clearance Self-Propelled Sprayers
• Machines retrofitted with the Case IH Pro 1200 Guidance Kit

1. 1

   Check System Info or Diagnostics tab on the AFS Pro display to view the exact status of the PCM and GNSS receiver

2. 2

   Inspect the coaxial/serial cables running from the PCM to the GNSS antenna for pinched wires, rubbed insulation, or crushed connectors

3. 3

   Disconnect the GNSS antenna from the harness; if the fault code changes to 520202-05 (Open Circuit), the short is internal to the antenna. If it remains 520202-06, the short is in the harness or PCM

4. 4

   Check for physical interference or obstructions (like tree branches) that could cause physical damage to the roof-mounted equipment

1. 1

   Power down machine

   Power down the machine and turn off the battery disconnect switch to protect the PCM.

2. 2

   Repair or replace wiring harness

   If the diagnostic checks isolate the short to the wiring harness, locate the damaged section (often near cab pass-throughs or roof mounts) and repair the wiring, or replace the specific antenna cable segment.

3. 3

   Replace GNSS antenna

   If the diagnostic checks isolate the short to the GNSS antenna, unbolt the antenna from its roof mounting bracket and disconnect the main harness. Install a replacement GNSS receiver.

4. 4

   Replace PCM

   If the harness and antenna test fine, the internal circuitry of the PCM providing power to the antenna has failed. Remove the PCM (usually located in the cab headliner or behind the seat depending on the model) and replace it.

5. 5

   Reconfigure system

   Power the system back on. The AFS Pro display should boot up. Navigate to the 'Measurements' and 'GNSS setup' screens to reconfigure the GNSS antenna position and ensure RTK/WAAS signals are being received.