Sumitomo SH300-6 Fault Code 7002: Complete Diagnostic Guide

What is Sumitomo SH300-6 Fault Code 7002?

Fault Code 7002 on the Sumitomo SH300-6 excavator indicates a Main Pump Control System Malfunction, specifically related to abnormal communication or voltage irregularities between the Engine Control Module (ECM) and the hydraulic pump servo control circuit. This code triggers when the control system detects signal values outside the manufacturer's specified range for the main pump's electro-hydraulic proportional control.

This fault is critical because the main pump control system directly regulates hydraulic flow and pressure based on operator demand and engine load. When this communication fails, the excavator cannot properly match hydraulic output to work requirements, leading to reduced performance and potential component damage. On used SH300-6 models, this code frequently appears due to electrical degradation in the aging wiring harnesses that connect the controller to the pump's servo solenoid valves.

Common Symptoms

• Erratic hydraulic performance with inconsistent boom or arm speeds despite steady joystick input
• Reduced digging force or sluggish response during combined hydraulic functions
• Intermittent warning light on the monitor panel, sometimes clearing after machine restart
• Engine RPM fluctuations when engaging hydraulics under load
• Hydraulic overheat warnings due to improper pump compensation and excessive system pressure

Potential Causes

The most common technical causes for Code 7002 on used SH300-6 excavators include:

• Corroded or loose connector pins at the main pump servo solenoid—a known wear point where the harness passes near the pump housing
• Damaged wiring harness between the cab-mounted controller and pump assembly, particularly where cables contact the swing bearing or turntable
• Failed servo solenoid coil within the main pump control valve (resistance typically measures 8-12 ohms when functional)
• ECM voltage supply issues providing incorrect reference voltage to the proportional control circuit
• Contaminated hydraulic oil causing servo valve spool sticking and abnormal current draw
• Worn pump control sensor providing erratic feedback signals to the ECM

How to Troubleshoot and Fix Code 7002

Step 1: Visual Inspection and Connector Check Begin by inspecting the main pump wiring harness from the controller to the servo solenoid. On used machines, check for abrasion points where the harness routes along the frame rail. Disconnect the servo solenoid connector and inspect for corrosion, bent pins, or moisture intrusion. Clean contacts with electrical contact cleaner and apply dielectric grease.

Step 2: Electrical Testing with Multimeter With the connector disconnected and ignition off, measure resistance across the servo solenoid coil terminals—should read 8-12 ohms. Next, check for voltage supply at the harness connector with ignition on (engine off): you should see approximately 12V reference voltage. If voltage is absent or fluctuating, trace back to the ECM and check for blown fuses or relay failures.

Step 3: Servo Solenoid Function Test Using Sumitomo diagnostic software (or compatible CAN bus scanner), command the servo solenoid through its range while monitoring current draw. Normal operation shows smooth current variation between 200-800mA. Erratic readings indicate internal coil or spool issues requiring solenoid replacement.

Step 4: Harness Continuity and Ground Testing For intermittent codes on used excavators, perform a wiggle test on the harness while monitoring live data. Check ground circuit integrity at both the pump housing and ECM—poor grounds cause voltage anomalies. Measure less than 0.5 ohms resistance to chassis ground.

Step 5: Hydraulic System Verification If electrical tests pass, verify hydraulic oil condition and filter status. Contaminated oil can cause servo valve sticking. Check system pressure with a test gauge—main relief should be 320-340 bar. Low pressure may indicate pump wear rather than control system failure.

Disclaimer: This guide provides general troubleshooting procedures for experienced technicians. Always consult the official Sumitomo service manual for your specific machine serial number. Complex electrical diagnostics or hydraulic pump repairs should be performed by certified professionals with proper training and equipment.