Sumitomo SH80-6B Fault Code P1244-2: Complete Diagnostic Guide

What is Sumitomo SH80-6B Fault Code P1244-2?

Fault Code P1244-2 indicates a hydraulic pump solenoid circuit malfunction, specifically a short-to-ground condition in the pump control solenoid valve circuit. This code is generated when the Electronic Control Module (ECM) detects abnormal electrical resistance or voltage drop in the main hydraulic pump's proportional solenoid valve wiring.

This fault directly affects the SH80-6B's load-sensing hydraulic system, which regulates pump displacement based on operational demand. The proportional solenoid valve controls hydraulic flow and pressure by adjusting pump swash plate angle. When this circuit fails, the excavator cannot properly modulate hydraulic power, leading to reduced performance and potential component damage. For used excavators, this code often signals wiring degradation or connector corrosion—common issues in machines with 5,000+ operating hours.

Common Symptoms

• Reduced hydraulic power across all functions (boom, arm, bucket, swing)
• Engine RPM fluctuations during simultaneous multi-function operations
• Intermittent fault code activation, especially during cold starts or wet conditions
• Hydraulic system operating in fixed displacement mode (no load-sensing modulation)
• Amber warning lamp illuminated on the instrument cluster with possible derate to protect the system

Potential Causes

The most frequent causes for P1244-2 on used SH80-6B excavators include:

• Damaged wiring harness near the main pump mounting area, where vibration causes insulation wear and ground contact
• Corroded or moisture-contaminated connectors at the solenoid valve (6-pin Deutsch connector common failure point)
• Failed proportional solenoid valve coil due to overheating or internal short circuit
• ECM internal driver circuit failure (less common but possible in high-hour machines)
• Pinched harness during previous pump removal/installation or undercarriage repairs
• Aftermarket harness repairs using improper gauge wire or inadequate insulation

How to Troubleshoot and Fix Code P1244-2

Step 1: Visual Inspection and Connector Check Disconnect the battery ground. Locate the hydraulic pump solenoid connector on the left side of the main pump assembly. Inspect for bent pins, green corrosion, oil contamination, or moisture inside the connector boot. On used excavators, carefully trace the harness from the pump to the ECM (mounted behind the operator's seat), checking for abrasion points where the harness contacts the chassis, especially near the swing bearing area.

Step 2: Electrical Testing with Multimeter Set your digital multimeter (DMM) to ohms mode. With the connector disconnected at the solenoid, measure resistance between each solenoid terminal and chassis ground. You should read >10kΩ (open circuit). A reading below 100Ω confirms a short-to-ground. Next, measure solenoid coil resistance across the two power terminals—specification is typically 8-12Ω at 20°C. Values outside this range indicate solenoid failure.

Step 3: Harness Continuity and Voltage Drop Test Reconnect the solenoid. Using back-probe pins at the ECM connector (C2, pins 14 and 27 for SH80-6B), check for continuity to the solenoid terminals with ignition OFF. Resistance should be <2Ω per wire. With ignition ON, measure voltage at the solenoid connector—should read battery voltage (12V) on the power supply wire. If voltage is present but code persists, perform a dynamic voltage drop test during actuation using Sumitomo diagnostic software or compatible tool.

Step 4: Repair or Replace Components For used machines, repair damaged harness sections using 18-gauge marine-grade wire with heat-shrink solder connections and protective loom. Apply dielectric grease to all connector pins before reassembly. If the solenoid valve tests faulty, replacement part number varies by pump manufacturer (typically Kawasaki K3V63DT)—verify using your serial number plate. After repairs, clear codes using diagnostic software and perform a 30-minute operational test under load.

---

Disclaimer: This guide provides general diagnostic procedures for informational purposes. Hydraulic system repairs involve high-pressure components and electrical systems. Always consult the official Sumitomo service manual for your specific serial number and consider professional diagnosis if unfamiliar with hydraulic or electrical troubleshooting procedures.