Case IH 520214-02 - PCM – PCM (Processing and Connectivity Module): The PCM cannot receive CAN messages to store diagnostic data snapshots

CAN bus communication failure on the CAN-2 network. The module is either receiving corrupted data packets, experiencing intermittent connection drops, or is entirely unable to read the CAN bus to log machine data.

• MAGNUM AFS Connect
• Magnum AFS Connect series
• Steiger AFS Connect tractors
• Optum tractors
• Puma tractors
• Patriot 50 Series sprayers
• Axial-Flow 260 Series combines
• Older legacy machines upgraded with the aftermarket PCM-F modem

1. 1

   Check Modem Status LED: Locate the PCM and verify the green LED for power. If blinking, the modem is updating over-the-air (do not interrupt). If steady ON, proceed to the next step.

2. 2

   Power Cycle: If the LED is steady but the CAN-2 error is active, cycle the power to the system (key off, wait for the battery disconnect relay to click off, then key on) to reboot the PCM.

3. 3

   Harness & Connection Inspection: Physically inspect the CAN connection to the modem. Look for backed-out pins, moisture intrusion, or corrosion at the PCM harness connector.

4. 4

   CAN Bus Voltage/Resistance Test: Probe the CAN-2 High and CAN-2 Low pins at the PCM connector. You should see approximately 60 ohms of resistance across the CAN network (with batteries disconnected). Check for shorts to ground or shorts to power on the CAN-2 lines.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Expose the PCM

   Locate the PCM (usually mounted in the cab roof or behind the right-hand console, depending on the tractor model).

3. 3

   Repair Wiring

   If the diagnostic checks revealed a broken wire or corroded pin on the CAN-2 network, splice the wire using OEM-approved weather-sealed connectors or repin the PCM connector.

4. 4

   Replace the PCM

   If the wiring harness tests perfectly (correct resistance and voltage) but the PCM still cannot read CAN-2 data, the PCM has suffered an internal hardware/I/O failure. Unbolt the PCM bracket, disconnect the main harness, the cellular antenna, and the GNSS/WiFi antennas, then install the new PCM and reconnect all antennas and harnesses.

5. 5

   Provisioning

   A new PCM will require a Case IH dealer technician to use the Electronic Service Tool (EST) to provision the modem, link it to your AFS Connect/FieldOps account, and flash the latest firmware.