Case IH 3767 (F-1648-12) - ECU – Engine Control Unit (ECU) / Electronic Diesel Control (EDC): ECU internal failure - 'WDA active' reported due to errors in query/response communication

The engine controller has detected an internal hardware or software processing error related to its internal query/response communication protocols, which has triggered a 'WDA' (Watchdog Active) safety state.

• VESTRUM CVX
• Farmall Tractors (40, 45, 50 with Cab and CVT)
• 240 Series Combines
• Steiger Tractors
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR175

1. 1

   Connect the CNH Electronic Service Tool (EST) to verify the code is active and not a historical anomaly.

2. 2

   Verify that the ECU is receiving proper and stable voltage, as severe voltage spikes or drops can sometimes cause internal processing faults (often accompanied by codes 3768 or 3769 for under/overvoltage).

3. 3

   Ensure the ECU harness connectors are fully seated and free of corrosion.

1. 1

   Replace the Engine Controller (ECU/EDC).

   According to the OEM service manual, an internal query/response communication failure is not repairable at the circuit level.

2. 2

   Install the new ECU onto the machine.

3. 3

   Connect the CNH Electronic Service Tool (EST).

4. 4

   Follow the appropriate service tool procedure to restore self-learning parameters and program the new engine controller to the specific machine and engine dataset (Engine Dataset Registration).

5. 5

   Clear the fault codes and cycle the key to ensure the code does not return.