Sumitomo SH220LC-6 Fault Code 117: Complete Diagnostic Guide

What is Sumitomo SH220LC-6 Fault Code 117?

Fault Code 117 on the Sumitomo SH220LC-6 excavator indicates a malfunction in the fuel injection system, specifically related to abnormal fuel injection timing or injector control circuit issues. This code is triggered when the Electronic Control Module (ECM) detects irregular signals from the fuel injection pump timing sensor or when injector solenoid circuits fall outside acceptable operating parameters.

This fault is critical for the SH220LC-6's performance because proper fuel injection timing directly affects engine power output, fuel efficiency, and emissions control. The Isuzu engine powering this excavator relies on precise electronic fuel delivery, and any deviation can result in reduced productivity and potential long-term engine damage.

Common Symptoms

When Code 117 is active on your SH220LC-6, operators typically experience:

• Engine power deration or noticeable loss of hydraulic performance during digging operations
• Check Engine Light (CEL) illuminated on the instrument cluster with possible warning buzzer
• Rough idling or inconsistent engine RPM, particularly during warm-up periods
• Black or gray exhaust smoke indicating incomplete combustion
• Hard starting conditions, especially after the machine has been sitting overnight or in cold weather

Potential Causes

The most common technical reasons for Code 117 on used SH220LC-6 excavators include:

• Fuel injection pump timing sensor failure due to heat exposure and age-related degradation
• Corroded or damaged wiring harness connections at the injector solenoids, particularly where harnesses run along the valve cover
• Failed injector solenoid circuits caused by internal coil breakdown or contaminated fuel
• ECM grounding issues from loose battery cables or corroded chassis ground points
• Worn fuel injection pump mechanical components affecting timing signal generation
• Contaminated diesel fuel causing injector sticking or erratic operation

How to Troubleshoot and Fix Code 117

Step 1: Initial Inspection and Data Retrieval Connect a diagnostic laptop with Sumitomo-compatible software (or universal heavy equipment diagnostic tools) to retrieve active and pending codes. Record freeze frame data showing engine conditions when the fault occurred. Check fuel quality and inspect the fuel water separator for contamination.

Step 2: Electrical System Verification Using a digital multimeter, verify battery voltage is 12.5-13V (engine off) and charging system maintains 13.8-14.4V at operating RPM. Inspect all injector harness connectors for corrosion, particularly at the engine valley where moisture accumulates on used machines. Check resistance across each injector solenoid (typically 0.5-2.0 ohms depending on specifications) and compare readings.

Step 3: Timing Sensor and Pump Inspection Locate the fuel injection pump timing sensor (mounted on the injection pump housing) and inspect the connector for oil contamination or pin corrosion. Test sensor output voltage while cranking (should produce AC voltage signal). On used excavators, check for harness chafing where cables contact the engine block or fuel lines.

Step 4: Component Testing and Replacement If electrical checks pass, perform an injector cut-out test using diagnostic software to isolate faulty injectors. Replace failed components with OEM or quality aftermarket parts. For used machines with high hours, consider replacing the entire injector wiring harness if multiple connection points show corrosion.

Disclaimer: This guide provides general troubleshooting procedures for informational purposes. Always consult the official Sumitomo service manual for your specific machine serial number and seek assistance from certified heavy equipment technicians for complex repairs involving fuel system components.