New Holland ENG 3405 – Engine ECU: ECU Power stages: Open load temperature error on the Turbocharger PWM output power stage

The Engine Control Unit (ECU) has detected an open circuit in the turbocharger wastegate (WG) signal wire. The ECU is unable to properly communicate with or control the Pulse Width Modulation (PWM) electric valve on the turbocharger due to a break in the circuit, a failed valve, or an internal ECU fault.

• T5.95
• T5.100
• T5.105
• T5.110
• T5.115
• T5.120
• T4.75
• T4.85
• T4.90
• T4.95
• T4.105
• T4.115
• TD5 Series
• L225
• L230
• C232
• C238
• W50C
• W60C
• W70C
• W80C
• B95C
• B110C
• U80C

1. 1

   Connect the Electronic Service Tool to verify if the fault code is currently active. Clear the code; if it does not return, the machine can be returned to service.

2. 2

   Inspect the Engine ECU connector (e.g., X-939) and the electric wastegate valve connector (e.g., X-960). Ensure all connections are secure, tight, and completely free of corrosion, abrasion, or bent pins.

3. 3

   Trace and inspect the wiring harness between the ECU and the turbocharger wastegate valve for any signs of chafing, breaks, or open circuits.

1. 1

   Repair Wiring

   If the diagnostic checks reveal damaged wiring or corroded connectors between the ECU and the turbocharger, repair or replace the affected harness section. Clear the code and test the machine.

2. 2

   Replace Wastegate Valve / Turbocharger

   If the wiring and connectors are fully intact and test good for continuity, the fault likely lies within the turbocharger's electric wastegate valve. Depending on the specific turbocharger revision, the PWM actuator may not be available separately, requiring a replacement of the turbocharger assembly.

3. 3

   Replace Engine ECU

   If both the wiring harness and the turbocharger wastegate valve are confirmed to be in working order, the Engine ECU has suffered an internal power stage failure and must be replaced and reprogrammed by a dealer.