Sumitomo SH210-6 Fault Code 7246: Technical Guide

What is Sumitomo SH210-6 Fault Code 7246?

Fault Code 7246 on the Sumitomo SH210-6 excavator indicates a malfunction in the hydraulic oil temperature sensor circuit, specifically a voltage signal that falls outside the expected range or a complete sensor failure. This diagnostic trouble code (DTC) is generated by the Electronic Control Module (ECM) when it detects abnormal resistance values or open/short circuit conditions in the temperature sensor wiring.

This fault is critical for the SH210-6 because the hydraulic oil temperature directly affects system viscosity, component lubrication, and overall hydraulic efficiency. The ECM uses this data to regulate pump output, activate warning systems, and protect the machine from thermal damage. When this sensor fails, the machine may enter a protective derate mode or operate without proper thermal management, risking catastrophic hydraulic system damage.

Common Symptoms

When Code 7246 is active on your Sumitomo SH210-6, operators typically experience:

• Hydraulic oil temperature warning light illuminated continuously on the instrument panel
• Reduced hydraulic performance or sluggish operation, especially during cold starts or heavy workloads
• ECM-triggered derate mode, limiting engine RPM or hydraulic pump flow to prevent overheating
• Erratic temperature gauge readings or gauge stuck at minimum/maximum positions
• Stored fault codes preventing the machine from passing pre-operation diagnostics

Potential Causes

The most common technical failures causing Code 7246 in used SH210-6 excavators include:

• Failed hydraulic oil temperature sensor due to age-related degradation or thermal cycling stress
• Damaged sensor wiring harness, particularly at known rub points near the hydraulic tank mounting brackets
• Corroded or loose connector pins at the sensor plug or ECM connection points (common in machines exposed to moisture)
• Short to ground or power in the sensor circuit wiring, often caused by harness chafing against frame components
• ECM internal faults (rare, but possible in high-hour machines with electrical system history)
• Contaminated hydraulic oil causing sensor element coating or failure

How to Troubleshoot and Fix Code 7246

Step 1: Visual Inspection Begin by locating the hydraulic oil temperature sensor (typically mounted on the hydraulic tank or return line). Inspect the sensor connector for corrosion, bent pins, or oil contamination. On used excavators, check the entire wiring harness from sensor to ECM for signs of rubbing, cracking, or previous repairs. Pay special attention to areas where the harness passes near sharp edges or moving components.

Step 2: Electrical Testing Disconnect the sensor and use a digital multimeter to measure resistance across the sensor terminals. Compare readings against Sumitomo specifications (typically 200-400 ohms at 20°C, varying with temperature). Test the harness for continuity and check for short circuits to ground using the ohm setting. Measure supply voltage at the connector with ignition on (should read approximately 5 volts reference signal from ECM).

Step 3: Component Replacement and Verification If the sensor tests outside specifications, replace it with a genuine Sumitomo or OEM-equivalent sensor. For used machines, always apply dielectric grease to connector pins before reassembly to prevent future corrosion. Clear the fault code using diagnostic software (Sumitomo diagnostic tool or compatible scan tool) and monitor during a complete heating cycle to confirm repair. If the code returns, inspect ECM grounds and consider ECM evaluation.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the official Sumitomo service manual for your specific serial number and consider professional diagnostic assistance for complex electrical issues or if you lack proper testing equipment.