Case IH 3672 – Engine ECU: EGR Valve Circuit - Short Circuit To Ground (A = 60pin Connector - Engine; A35)

The system has detected that the output circuit 2 (Out2), which corresponds to pin A35 on the 60-pin engine connector, is shorted to ground. The "H-bridge" is the internal circuitry used to drive the DC motor of the Exhaust Gas Recirculation (EGR) valve actuator.

• Farmall
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR175

1. 1

   Inspect the wiring harness between the Engine ECU (60-pin connector) and the EGR valve actuator for chafing, melting, or exposed wires

2. 2

   Disconnect the ECU and EGR valve, then use a multimeter to test the wire corresponding to ECU Pin A35 for continuity to ground

3. 3

   Test the EGR valve actuator pins for an internal short to ground

4. 4

   Check the vehicle's electrical system for high voltage fluctuations, which can cause H-bridge errors and damage the ECU

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical damage.

2. 2

   Isolate the Short

   Disconnect the 60-pin connector at the Engine ECU and the connector at the EGR valve.

3. 3

   Repair Wiring

   If your multimeter shows continuity to ground on the Pin A35 circuit while both ends are disconnected, the wiring harness is shorted. Locate the short and repair or replace the damaged section of the harness.

4. 4

   Replace EGR Valve

   If the wiring harness tests good, the short is likely internal to the EGR valve actuator. Replace the EGR valve.

5. 5

   ECU Replacement (If Necessary)

   If the wiring and EGR valve are both in good working order, or if the fault persists after replacing them, the Engine ECU's internal H-bridge may be permanently damaged. In this case, replace the Engine Controller.

6. 6

   Calibration

   If the EGR valve or the Engine ECU is replaced, you must use the appropriate electronic service tool to restore self-learning parameters and calibrate the new components.