New Holland ENG 3669 – ENGINE: EGR Short to Battery on EGR Out1 pin A50 error for H-bridge

The engine control system has detected a short circuit to battery voltage on the control circuit for the Exhaust Gas Recirculation (EGR) valve actuator. Specifically, the error is traced to Output 1 on pin A50 of the ECU.

• L220
• L230
• SR175
• SV185
• SR130
• SR150
• SR200
• SR220
• SR250
• SV250
• SV300

1. 1

   Visual Inspection: Inspect the wiring harness running between the Engine ECU and the EGR valve actuator for any signs of chafing, melting, or damage that could cause a wire to short to a 12V power source.

2. 2

   Pin A50 Circuit Test: Disconnect the harness from the Engine ECU and the EGR valve. Using a multimeter, test the specific wire corresponding to ECU pin A50 (EGR Out1) for continuity to battery voltage.

3. 3

   Connector Check: Inspect the connectors at both the Engine ECU and the EGR valve for corrosion, water intrusion, or bent pins that could bridge the circuits.

4. 4

   Actuator Internal Short Test: Test the EGR valve actuator itself to determine if the internal motor has shorted to power.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent electrical damage during testing.

2. 2

   Isolate the Circuit

   Disconnect the wiring harness connector at the EGR valve actuator and the main connector at the Engine ECU.

3. 3

   Test the Harness

   Probe the wire for pin A50 (EGR Out1). If your multimeter shows voltage or continuity to a battery power wire, the wiring harness is shorted.

4. 4

   Repair/Replace Harness

   If a short is found in the harness, locate the damaged section and repair the wires using proper soldering and heat-shrink techniques, or replace the engine wiring harness entirely.

5. 5

   Replace the EGR Actuator

   If the wiring harness tests good (no short to battery), the short is likely internal to the EGR valve actuator. Replace the EGR valve/actuator assembly.

6. 6

   ECU Replacement (Worst Case)

   If both the harness and the EGR actuator test perfectly fine, the H-bridge driver inside the Engine ECU has failed internally. The Engine ECU will need to be replaced and reprogrammed.

7. 7

   Clear Codes

   Reconnect all components and the battery. Use the New Holland Electronic Service Tool (EST) or a compatible CAN-Bus DTC eraser to clear the ENG 3669 fault code from the engine ECU.