Case IH 3670 – Engine Control Unit (ECU): EGR Valve Circuit - Short Circuit To Battery (A = 60pin Connector - Engine; A35)

The engine controller has detected a short circuit to battery voltage on the 'Out 2' circuit for the H-bridge that drives the Exhaust Gas Recirculation (EGR) valve actuator.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Backhoe Loaders (580N, 580ST, 575N)
• Farmall series tractors

1. 1

   Check the vehicle's electrical system for high voltage fluctuations, which can cause this code to trigger and potentially damage the ECU

2. 2

   Inspect the engine wiring harness between the EGR valve and the Engine ECU, specifically probing the 'A' 60-pin engine connector at Pin A35 to test for a short circuit to battery voltage

3. 3

   Check if the EGR valve is physically blocked or sticking in the closed position, which can sometimes overload the circuit

1. 1

   Disconnect battery

   Disconnect the machine's battery to ensure safety before servicing the electrical system.

2. 2

   Repair or replace wiring harness

   If a short to battery is found during the wiring harness test, repair the damaged wires or replace the engine wiring harness.

3. 3

   Replace EGR Valve

   If the wiring harness tests good but the fault remains, replace the EGR Valve assembly.

4. 4

   Replace Engine Controller (ECU)

   If the fault persists after replacing the EGR valve, or if the system experienced severe high voltage fluctuations that fried the circuit, replace the Engine Controller (ECU).

5. 5

   Reconnect battery

   Reconnect the battery.

6. 6

   Clear codes and calibrate

   Connect the appropriate OEM diagnostic service tool (CNH Electronic Service Tool). Clear the fault codes and execute the procedure to 'Restore Self Learning Parameters' (also listed as 'Reset ECU data for EGR valve') so the ECU can calibrate to the new components.