Case IH 522826-05 - PCM – PCM: WiFi/BT Antenna Open Circuit

The Failure Mode Indicator (FMI) '05' signifies 'Current below normal or open circuit'. This means the control module is not detecting electrical continuity to the Wi-Fi/Bluetooth antenna, indicating that the circuit is broken, unplugged, or the antenna itself has failed internally.

• MAGNUM AFS Connect
• Magnum AFS Connect series
• Steiger and Quadtrac series
• Optum and Puma tractors
• Axial-Flow combines (e.g., 250 and 260 series)
• Patriot 50 Series sprayers

1. 1

   Check the green LED power light on the PCM modem (steady ON means it has power; blinking means firmware is updating and should not be interrupted)

2. 2

   Cycle the power to the system to see if the code clears (if the LED is steady ON)

3. 3

   Physically inspect the Wi-Fi/Bluetooth antenna cable connection at the PCM to ensure it is fully seated and locked

4. 4

   Trace the antenna cable from the PCM to the roof mount to check for pinched wires, cuts, or disconnected inline connectors

1. 1

   Power down machine

   Power down the machine and turn off the battery disconnect switch.

2. 2

   Locate PCM

   Locate the PCM (usually mounted in the cab roof or behind the interior trim, depending on the specific tractor/combine model).

3. 3

   Inspect antenna cable

   Disconnect the Wi-Fi/BT antenna cable from the PCM. Inspect the pins for corrosion or damage.

4. 4

   Test wiring harness

   If the wiring harness is visibly damaged or tests open with a multimeter, the antenna must be replaced.

5. 5

   Access cab roof

   To replace the antenna, access the vehicle's cab roof. The PCM dual-mode antenna is typically mounted on a flat surface at the highest possible point of the cab roof using adhesive pads, with the cable exiting toward the rear.

6. 6

   Remove old antenna

   Remove the old antenna and clean the mounting surface.

7. 7

   Route new antenna cable

   Route the new antenna cable through the roof access point down to the PCM, ensuring it is not pinched by interior trim panels.

8. 8

   Secure new antenna

   Secure the new antenna to the roof using the provided adhesive pad.

9. 9

   Verify repair

   Reconnect the antenna to the PCM, restore battery power, and cycle the ignition to verify the 522826-05 fault code has cleared.