Case IH 520202-05 - PCM – PCM: GNSS antenna open circuit

The control module has detected a break in the electrical connection to the Global Navigation Satellite System (GNSS) antenna. An "open circuit" means the electrical path is incomplete, which is typically caused by a disconnected cable, a severed wiring harness, damaged connector pins, or an internal hardware failure within the antenna/receiver itself.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect series
• Case IH Puma series
• Other Case IH equipment utilizing the Pro 1200 display and PCM retrofit kits

1. 1

   Visually inspect the GNSS antenna (usually mounted on the cab roof) and its wiring harness for obvious physical damage, cuts, or pinches.

2. 2

   Check the coaxial/electrical connectors at both the GNSS antenna and the PCM. Ensure they are fully seated, tight, and free of moisture, dirt, or bent pins.

3. 3

   Use a multimeter to check for continuity along the antenna cable from the PCM to the roof mount to rule out a severed wire hidden inside the cab pillars or headliner.

4. 4

   Verify that the PCM is outputting the correct reference voltage to the antenna connector.

1. 1

   Power down

   Turn off the tractor and disconnect battery power to prevent short circuits during repair.

2. 2

   Repair wiring harness

   If the diagnostic checks reveal a broken wire or damaged connector, repair the wiring harness or replace the specific cable segment routing to the cab roof.

3. 3

   Determine if antenna replacement is needed

   If the wiring harness tests perfectly but the open circuit code remains active, the internal circuitry of the GNSS receiver has failed and requires replacement.

4. 4

   Dismount the antenna

   Remove the faulty GNSS receiver from its mounting bracket on the cab roof.

5. 5

   Install new antenna

   Mount the replacement GNSS receiver, ensuring it has an unobstructed 360-degree view of the sky and is mounted directly above the equipment's control point.

6. 6

   Reconnect and clear codes

   Reconnect the harness, restore power, and use the AFS display or a diagnostic tool to clear the 520202-05 fault code. Verify that satellite tracking resumes.