New Holland NH 14902 – Tractor ECU (Gateway) / Instrument Cluster (ADIC): Auxiliary (optional) Controller Module missing (DD/DH)

The main tractor network has lost CAN bus communication with the auxiliary control module. The system expects to see this module on the data bus, but it is not receiving any data or "handshake" signals from it, prompting the system to flag it as missing or disconnected.

• T5000 Series
• T5070
• T6000 Series
• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• T7000 Series
• T7 Series
• TL-A Series
• TL90a
• TS Series
• TS-A Series
• TM Series
• TM 175

1. 1

   Check for multiple CAN bus communication codes (such as 14900 or 14903). Multiple missing module codes usually indicate a severed CAN bus line or a failed Gateway rather than a single bad module.

2. 2

   Inspect the wiring harness running to the Auxiliary Controller (XCM) for chafing, breaks, or rodent damage, paying special attention to areas where the harness routes near the cab panels or transmission housing.

3. 3

   Test the power (12V) and ground circuits at the Auxiliary Controller's connector. If the module is not receiving power, it cannot communicate on the CAN bus.

4. 4

   Disconnect the plugs at the Auxiliary Controller (e.g., CN1-A, CN2, CN3-A, CN3-B, CN4) and inspect the pins for corrosion, moisture, or pushed-back terminals.

1. 1

   Park and disconnect battery

   Park the tractor on a level surface, turn off the ignition, and disconnect the negative battery terminal to prevent electrical shorts.

2. 2

   Locate module

   Locate the Auxiliary Controller Module (XCM). Depending on the tractor model, this is typically located inside the cab behind the right-hand console, under the armrest, or behind the side trim panels.

3. 3

   Disconnect connectors

   Disconnect the multi-pin wiring harness connectors from the module.

4. 4

   Clean connectors

   Spray the connectors with a high-quality electrical contact cleaner and allow them to dry. Reconnect them firmly to ensure the issue wasn't simply a loose connection.

5. 5

   Test connection

   Reconnect the battery and turn the key to the ON position. If the code clears, the issue was a poor connection.

6. 6

   Disconnect battery

   If the code persists and all wiring/power checks have passed, the Auxiliary Controller itself has likely failed internally. Disconnect the battery again.

7. 7

   Remove faulty unit

   Unbolt the mounting hardware securing the Auxiliary Controller and remove the faulty unit.

8. 8

   Install replacement

   Install the replacement Auxiliary Controller and secure it with the mounting hardware.

9. 9

   Reconnect connectors

   Reconnect the wiring harness connectors until they click into place.

10. 10

    Reconnect battery and calibrate

    Reconnect the battery. Note: A new controller module may require a software flash or CAN bus calibration using the New Holland Electronic Service Tool (EST) by an authorized dealer to be properly recognized by the tractor's Gateway.