New Holland NH 14907 – CAN Network / Main Vehicle ECU (or Transmission Controller): DOG (Display Of Gears) missing

The main controller is no longer receiving data signals from the Gear Display Module (DOG), indicating a CAN bus communication error.

• TM115
• TM120
• TM125
• TM130
• TM135
• TM140
• TM150
• TM155
• TM165
• TM175
• TM190
• T6.175

1. 1

   Verify battery voltage and charging system stability; low voltage during cranking or operation can cause the module to temporarily drop off the CAN network.

2. 2

   Check the cab ground connections, frame grounds, and the battery negative cable for high ground resistance.

3. 3

   Access the Gear Display Module and inspect its wiring harness connector for moisture, corrosion, or backed-out pins.

4. 4

   Using a multimeter, verify that the module is receiving switched power and a clean ground.

5. 5

   Test the CAN bus network for proper resistance (typically 60 ohms across CAN High and CAN Low) to ensure the communication lines are intact.

1. 1

   Disconnect Power

   Turn off the tractor ignition and disconnect the negative battery terminal to prevent electrical shorts.

2. 2

   Access the Module

   Locate the Gear Display Module (DOG), which is typically mounted in the cab on the A-pillar or integrated into the dashboard area.

3. 3

   Inspect and Clean

   Disconnect the wiring harness from the module. Clean the connector pins with electrical contact cleaner. If wiring damage is found, repair the harness.

4. 4

   Replace the Module

   If power, ground, and CAN lines test good but the module remains unresponsive, the internal circuitry of the DOG has failed. Remove the mounting hardware, extract the old module, and install the replacement unit.

5. 5

   Reassemble and Clear Codes

   Reconnect the wiring harness and the battery. Turn the ignition on and use the tractor's inbuilt self-diagnostic facility (via the instrument cluster) or a diagnostic tool to clear the stored NH 14907 fault code. Verify that the gear display powers up and accurately reflects the transmission state.