New Holland NH 14900 – Instrument Cluster / CAN Network Gateway: Transmission module missing (DA/DB/DE/DF)

The instrument cluster or main data gateway has lost CAN network communication with the transmission controller.

• New Holland T5 Series (T5.95, T5.105, T5.115)
• New Holland T7 Series
• New Holland TL-A Series (TL90a)
• New Holland Workmaster 50

1. 1

   Test the battery voltage to ensure it is approximately 12 to 14 volts (low voltage or overcharging can cause modules to shut down)

2. 2

   Monitor 'TRANS BATTERY VOLTAGE' using the dealer service tool (EST) or check the instrumentation display for 'BATT' in the TRANS VIEW menu to see if the module is receiving power

3. 3

   Inspect the CAN bus wiring harness between the instrument cluster and the transmission controller for corrosion, water intrusion, vibration fractures, or bad grounding

4. 4

   Pin out the transmission controller's harness connector to verify it is receiving stable switched power, constant power, and a solid ground

1. 1

   Disconnect Power

   Disconnect the negative battery cable before servicing the CAN network or unplugging modules.

2. 2

   Clean Connections

   Disconnect the harness at the Transmission Controller. Treat the pins and the connector with a high-quality electrical contact cleaner to remove any hidden corrosion or moisture.

3. 3

   Repair Wiring

   If the diagnostic checks revealed chafed wires, broken CAN lines (CAN High / CAN Low), or a bad ground, repair the wiring harness using proper soldering and heat-shrink techniques.

4. 4

   Replace the Module (If Necessary)

   If the wiring harness, power, and ground are all verified as good, but the module still will not communicate on the network, the Transmission Controller itself has failed internally and must be replaced.

5. 5

   Calibrate the New Module

   If the transmission controller is replaced, you must perform a transmission calibration routine using the New Holland Electronic Service Tool (EST) software, as the new module will not have the clutch fill times and shift parameters learned for that specific tractor.