New Holland ENG 3418 – Engine ECU: Turbocharger - ECU Power stages: SCB error on the Turbocharger PWM output power stage

The Engine Control Unit (ECU) has detected a short to battery voltage (or an excess current draw / failed high circuit) in the turbocharger wastegate actuator signal wire.

• W50C ZB
• W60C ZB
• W70C HS
• W70C
• W80C HS
• W80C
• L175
• L180
• L185
• L220
• L230
• C175
• C185
• C227
• C232
• T5.75
• T5.85
• T5.95
• T5.100
• T5.105
• T5.110
• T5.115
• T5.120
• TD5.85
• TD5.95
• TD5.105
• TD5.115
• T6
• T7
• T8
• T9

1. 1

   Connect the Electronic Service Tool (EST) to the diagnostic connector to confirm fault code 3418 is active and verify there are no other codes indicating high battery voltage to the ECU.

2. 2

   Inspect the wiring harness running from the Engine ECU to the turbocharger wastegate actuator for damage, corrosion, abrasion, or incorrect attachment.

3. 3

   Ensure the connectors at both the ECU and the wastegate actuator are secure and free of bent or corroded pins.

4. 4

   Turn the key switch OFF, disconnect the ECU and wastegate actuator connectors, and measure the resistance of the signal wires to chassis ground and across the relevant ECU pins to check for a short to battery. Wiggle the harness during measurement to reveal any intermittent shorts.

5. 5

   Isolate the component failure: determine if the fault lies in the wiring, the electric valve (wastegate actuator), or the ECU. If the wiring tests perfectly, the actuator itself is likely shorted internally.

1. 1

   Wiring Repair

   If a short to battery is found in the harness, repair or replace the affected section of the wiring harness or connectors.

2. 2

   Actuator / Turbocharger Replacement

   If the wiring is intact, the wastegate actuator is faulty. Replace the turbocharger assembly or utilize an exact-fit aftermarket CHRA/actuator core. Remove the hoses running from the turbocharger to the boost pressure modulator valve and the Throttle Valve Actuator (TVA). Remove the oil supply line from the top of the turbocharger and the oil drain tube from the bottom. Unbolt the turbocharger from the exhaust manifold mounting flange and remove it. Install the new turbocharger with a new gasket onto the exhaust manifold. Torque the mounting nuts to 20 - 30 N·m (15 - 22 lb ft). Reinstall the oil drain tube (with a new gasket) and the oil supply line. Reconnect all air hoses and the electrical connector for the wastegate actuator.

3. 3

   ECU Replacement

   If both the wiring and the actuator test good, the Engine ECU has a failed power stage and must be replaced.

4. 4

   Clear Codes

   Use the EST or a CAN-Bus DTC eraser to clear the codes. Start and operate the machine to verify code 3418 does not return.