Case IH 277 – Engine Control Module (ECM / ENG): Injection Control Valve is failed

The Engine Control Module (ECM) has detected an open or short circuit in the Injection Control Valve (ICV).

• MX Magnum
• STX Steiger
• MX240
• MX255
• MX270
• MX285
• 215
• 245
• 275
• 305
• 335
• STX275
• STX325
• STX440
• 5088
• 6088
• 7088
• TG210
• TG230
• TG255
• TG285
• T8000 series

1. 1

   Check for accompanying Fault Code 539 (Transient Suppressor Circuit), which indicates the transorb diode has degraded and allowed voltage spikes to hit the ECM (points to electrical failure cause).

2. 2

   Review ECM snapshot data for battery voltage drops below 9-VDC at the exact moment the 277 code was logged, which is a primary indicator of a shorted stator.

3. 3

   Inspect the engine wiring harness between the ECM (specifically at Pin A7) and the ICV for chafing, broken wires, or corrosion, and ensure the ECM has a solid ground connection.

4. 4

   Inspect the pump for broken check valve springs (mechanical failure cause), but do NOT remove the threaded plugs directly to avoid voiding rebuildability or causing further damage.

1. 1

   Repair the Transient Suppressor Diode (If Code 539 is present)

   Locate the transorb diode in the engine harness (a copper cylinder about 0.5" in diameter and 3" long, located roughly 8 inches from the ECM). Cut the failed diode out of the harness and solder a new one in its place to protect the ECM from further voltage spikes.

2. 2

   Replace the Stator / ICV Assembly

   If the failure is purely electrical (shorted stator), you can replace just the ISC-Equalizer/Stator and the Suppressor Diode. If the ICV is mechanically damaged by spring debris from the pump, the entire Injection Control Valve assembly must be replaced.

3. 3

   Clear Codes and Test

   After replacing the ICV/Stator and the transorb diode, clear the ECM codes and run the engine to check for normal operation.

4. 4

   Evaluate the CAPS Pump

   If the tractor continues to lose power, fails to prime, or throws over-pumping codes (like Code 329), the internal mechanical failure of the CAPS injection pump is likely severe enough to warrant a complete pump rebuild or replacement.