What is Sany Excavator Fault Code P116?

Fault Code P116 on Sany excavators indicates a Fuel Injector Circuit Malfunction for Cylinder #6, signaling that the Engine Control Module (ECM) has detected an abnormal electrical resistance, voltage, or response time in the injector circuit. This diagnostic trouble code (DTC) specifically points to communication or power delivery issues between the ECM and the fuel injector solenoid on the sixth cylinder.

In Sany's common rail diesel systems, precise fuel injector operation is critical for maintaining optimal combustion timing, engine power, and emissions compliance. When the ECM cannot properly energize or monitor cylinder #6's injector, fuel delivery becomes inconsistent, leading to rough running, power loss, and increased exhaust smoke. For used excavators, this code often surfaces due to age-related electrical degradation rather than mechanical injector failure.

Common Symptoms

• Rough idling or noticeable engine vibration, especially at low RPM
• Black or white smoke from the exhaust during operation
• Reduced engine power or hesitation under load conditions
• Check Engine Light illuminated on the instrument cluster
• Fuel consumption increase due to incomplete combustion in cylinder #6

Potential Causes

The most common technical causes for Code P116 on used Sany excavators include:

• Damaged injector wiring harness – particularly at rub points near the valve cover or engine block where vibration causes insulation wear
• Corroded or loose electrical connectors at the injector or ECM (common in machines exposed to moisture or extreme temperatures)
• Failed fuel injector solenoid on cylinder #6 due to coil winding breakdown
• ECM internal driver circuit failure affecting only the #6 cylinder output
• Intermittent short circuits caused by damaged harness insulation contacting metal surfaces
• Poor ground connections at engine block grounding points

How to Troubleshoot and Fix Code P116

Step 1: Visual Inspection Begin by inspecting the injector wiring harness for cylinder #6. Look for abraded insulation, pinched wires at mounting brackets, or connector corrosion. On used excavators, check harness routing near the valve cover gasket where oil leaks commonly damage insulation.

Step 2: Electrical Testing Using a digital multimeter, measure injector solenoid resistance at the connector (typically 0.3-0.7 ohms for Sany common rail injectors). Test supply voltage from the ECM with ignition on (should read battery voltage). Check for continuity to ground, which indicates a short circuit.

Step 3: Swap Testing If resistance and voltage are within specification, swap the cylinder #6 injector connector with another cylinder. Clear codes and run the engine. If the fault moves to the new cylinder, the injector solenoid is faulty. If P116 remains on cylinder #6, suspect ECM driver circuit or harness issues.

Step 4: Connector and Ground Service Clean all electrical connectors with contact cleaner and apply dielectric grease. Verify engine block ground strap connections are tight and corrosion-free—a common issue in high-hour used machines.

Step 5: Component Replacement Replace confirmed faulty components: injector, harness section, or consult a Sany technician for ECM replacement if driver circuits are damaged.

---

Disclaimer: This guide provides general troubleshooting information. Always consult Sany service manuals and qualified diesel technicians for your specific excavator model, especially when working with high-pressure fuel systems.