Sumitomo SH290-5 Fault Code 1113: Complete Diagnostic Guide

What is Sumitomo SH290-5 Fault Code 1113?

Fault Code 1113 on the Sumitomo SH290-5 excavator indicates a malfunction in the Engine Speed Sensor (ESS) circuit, specifically detecting an abnormal voltage signal or intermittent connection between the sensor and the Engine Control Module (ECM).

This code triggers when the ECM detects voltage readings outside the normal operating range (typically 0.5-4.5V) from the engine speed sensor, also known as the crankshaft position sensor. The engine speed sensor is critical for proper fuel injection timing, engine RPM regulation, and overall performance monitoring on the Sumitomo SH290-5's diesel engine. When this circuit fails, the ECM cannot accurately determine engine speed, which directly impacts fuel delivery, power output, and emissions control.

For used excavators, this fault becomes particularly problematic as it can cause the machine to enter derate mode or prevent starting altogether, significantly affecting jobsite productivity.

Common Symptoms

When Code 1113 is active on your SH290-5, operators typically experience:

• Check Engine Light or malfunction indicator illuminated on the instrument panel
• Hard starting conditions or complete failure to start, especially when the engine is cold
• Rough idling or irregular engine speed fluctuations during operation
• Loss of power or unexpected engine derating at higher RPMs
• Intermittent stalling during normal operation or when returning to idle

Potential Causes

The most common technical causes for Code 1113 on used Sumitomo SH290-5 excavators include:

• Faulty engine speed sensor due to internal component degradation or bearing wear contamination
• Damaged wiring harness between the sensor and ECM, particularly at flex points near the engine mount or along the frame rail where abrasion commonly occurs
• Corroded or loose connector terminals at the sensor plug or ECM interface—extremely common in machines with high operating hours
• Broken or damaged reluctor ring (tone wheel) on the crankshaft or flywheel
• ECM internal fault affecting the sensor input circuit (rare, but possible in high-hour machines)
• Poor grounding at the sensor mounting point due to rust, paint buildup, or loose mounting bolts

How to Troubleshoot and Fix Code 1113

Step 1: Visual Inspection Begin by locating the engine speed sensor, typically mounted on the bell housing or timing cover facing the flywheel. Inspect the sensor body for physical damage, oil contamination, or metal debris accumulation. Check the air gap between the sensor tip and reluctor ring—it should be 0.020-0.040 inches. On used excavators, verify the mounting bracket isn't cracked and the sensor hasn't shifted position.

Step 2: Electrical Testing Disconnect the sensor harness connector and inspect both male and female terminals for corrosion, bent pins, or moisture intrusion. Using a digital multimeter, measure sensor resistance across the two terminals—typical readings should be 200-1000 ohms (consult your service manual for exact specifications). Next, check for voltage supply from the ECM with the key on, engine off; you should see approximately 5V reference voltage.

Step 3: Wiring Harness Verification Trace the sensor wiring from the sensor back to the ECM, checking for damaged insulation, particularly where the harness passes through grommets, near hot exhaust components, or contacts the frame. Perform a continuity test on each wire and check for shorts to ground. For used machines, pay special attention to harness routing—previous repairs may have created new wear points.

Step 4: Dynamic Testing and Component Replacement If wiring checks pass, use Sumitomo diagnostic software (or compatible scan tool) to monitor live sensor data while cranking the engine. The ECM should show varying frequency signals. If no signal appears with good wiring, replace the engine speed sensor with an OEM or quality aftermarket unit. After replacement, clear codes and verify proper air gap adjustment before testing.

Professional Tip: Before ordering expensive parts for used excavators, always clean all connector contacts with electrical contact cleaner and apply dielectric grease—corrosion alone causes this code in approximately 40% of cases.

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Disclaimer: This guide provides general troubleshooting information for Sumitomo SH290-5 excavators. Always consult the manufacturer's service manual for exact specifications and procedures. If you're uncomfortable performing electrical diagnostics, contact a certified Sumitomo technician or qualified heavy equipment mechanic to prevent further damage to your machine's electrical system.