Case IH 14126 – APM Control Unit / Module: APM - Missing

The central vehicle controller or CAN bus network has lost communication with the APM (Automatic Productivity Management) control module. The system expects the APM node to be present on the network, but it is not receiving a heartbeat or data signal.

• MAXXUM T4E
• Case IH Magnum Series (250, 310, 340, 380, 400)
• Case IH Puma Series (150, 155, 165, 185, 225)
• Case IH Optum Series (270, 300, 340)
• Case IH Maxxum CVX Series (115-150)
• Case IH Vestrum CVXDrive Series (100-130)
• Case IH Steiger Series

1. 1

   Verify that the APM is correctly configured in the tractor's software (check for related code 14127 to ensure the configuration file is not lost)

2. 2

   Check the fuses and relays supplying power to the APM module, and use a multimeter to verify proper voltage and a solid ground connection

3. 3

   Inspect the CAN High and CAN Low communication lines leading to the APM module for open circuits, shorts to ground, or shorts to voltage

4. 4

   Perform a network scan for other 'Missing' module codes (e.g., 14900 Transmission controller missing, 14901 Engine controller missing) to determine if the issue is a severed CAN bus backbone line rather than a single module failure

1. 1

   Access the Module

   Locate the APM control module (often integrated into the cab electronics or Multicontroller armrest area, depending on the specific tractor model).

2. 2

   Inspect Wiring

   Disconnect the harness from the APM module. Inspect the connector pins for corrosion, pushed-back pins, or moisture intrusion. Clean with contact cleaner if necessary.

3. 3

   Test the Harness

   With the batteries disconnected, measure the terminating resistance of the CAN bus at the APM connector (it should read approximately 60 ohms).

4. 4

   Replace the Module

   If the wiring, power, ground, and CAN resistance all test within specification, the APM module has suffered an internal failure and must be replaced.

5. 5

   Flash and Configure

   Install the new APM module. Connect a dealer diagnostic tool (such as the CNH Electronic Service Tool or Jaltest) to flash the correct software onto the new module.

6. 6

   Clear Codes

   Perform a network reconfiguration so the TECU recognizes the new APM module, clear the 14126 fault code, and test drive the tractor in 'Auto Field' or 'Auto Road' mode to verify APM functionality.