New Holland ENG 3677 – Engine ECU (Engine Control Module / EDC): EGR DFC for valve position sensor voltage SRC low

The Engine Control Unit (ECU) has detected that the voltage signal returning from the Exhaust Gas Recirculation (EGR) valve position sensor is below the normal operating threshold (Signal Range Check - Low). This typically indicates a short to ground in the sensor signal circuit, an open circuit (broken wire or disconnected plug), or an internal failure of the EGR valve position sensor itself.

• L213
• L216
• L220
• C227
• C232
• C327
• T4.75
• T4.100F
• T5.110
• T5.130
• B90B
• B100B
• B115B

1. 1

   Inspect the wiring harness and connector at the EGR valve for corrosion, backed-out pins, or chafing against the engine block.

2. 2

   Disconnect the EGR valve connector and measure the voltage between the position sensor power supply pin (usually Pin 1) and the sensor ground pin (usually Pin 3) on the harness side with the key ON. It should read approximately 5.0 Volts.

3. 3

   Measure the voltage at the EGR valve motor power pins (typically Pin 6 and Pin 2) to ensure the valve actuator is receiving proper voltage (12V or 24V depending on the machine's system).

4. 4

   Check the signal wire from the EGR connector back to the Engine ECU for continuity and ensure it is not shorted to ground.

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the negative battery cable. Allow the engine and exhaust system to cool completely.

2. 2

   Access the EGR Valve

   Locate the EGR valve assembly on the engine (typically mounted near the exhaust manifold and EGR cooler).

3. 3

   Disconnect Electrical and Plumbing

   Unplug the electrical connector from the EGR valve actuator. If your model features coolant lines routed to the EGR valve, drain a small amount of coolant and disconnect the lines.

4. 4

   Remove the Valve

   Remove the mounting bolts securing the EGR valve to the intake/exhaust manifolds and the EGR cooler pipe.

5. 5

   Clean Mating Surfaces

   Carefully remove the old EGR valve and scrape away any leftover gasket material or heavy carbon buildup from the manifold ports.

6. 6

   Install the New Valve

   Position the new EGR valve with new OEM gaskets. Thread the mounting bolts by hand to prevent cross-threading, then torque them to the manufacturer's specification.

7. 7

   Reassembly

   Reconnect the EGR cooler lines (if applicable) and plug in the electrical connector.

8. 8

   ECU Reset

   Reconnect the battery. You must use a diagnostic scan tool (such as the New Holland Electronic Service Tool) to clear the ENG 3677 fault code and perform an "EGR Valve Reset / Relearn" procedure in the ECU data so the computer can learn the new sensor's closed/open voltage limits.