New Holland ENG 3748 – Engine Control Unit (ECU) / Electronic Diesel Control (EDC): EDC - Power stages, Injector: Diagnostic fault check to report the timed out in the shut off path test.

The Engine Control Unit (ECU) has detected an internal processing error during the ECU startup sequence. Specifically, the diagnostic check monitoring the injector power stages (the circuits responsible for firing the fuel injectors) timed out while running its mandatory shut-off path safety test.

• Skid Steer Loaders (L220, L228)
• Compact Track Loaders (C227, C232)
• T4 Series Tractors
• T5 Series Tractors

1. 1

   Confirm that the fault code is currently active and not a stored historical code triggered by a low battery event

2. 2

   Inspect the output stage circuit, checking for open wires, short circuits, and ensuring the ECU is receiving proper voltage from the power supply

3. 3

   Check if the ECU requires a software/firmware update, as this is often a software processing error during startup

1. 1

   Flash the ECU

   Connect the New Holland Electronic Service Tool (EST) and reload the engine dataset (flash the ECU) with the most current software.

2. 2

   Re-test

   Cycle the key and allow the ECU to perform its startup checks to see if the timeout error clears.

3. 3

   Replace the ECU

   If the error persists after successfully flashing the controller, the internal power stages of the ECU are permanently damaged, and the Engine Controller (EDC) must be replaced.

4. 4

   Restore Parameters

   If the EDC is replaced, you must use the EST service tool to restore the engine's self-learning parameters and injector calibration codes to the new module.