What is Hyundai R805LC-7 Fault Code 1244-5?

Fault Code 1244-5 on the Hyundai R805LC-7 excavator indicates a Main Relief Valve Solenoid Current Below Normal or Open Circuit condition. This Failure Mode Identifier (FMI-5) specifically signals that the Electronic Control Unit (ECU) has detected abnormally low electrical current or a complete loss of current flowing through the main relief valve solenoid circuit. The main relief valve solenoid is critical for regulating maximum hydraulic system pressure—when this circuit fails, the excavator's hydraulic safety parameters and performance optimization are compromised.

This fault affects the hydraulic control system directly, which on the R805LC-7 manages pressure regulation across the primary hydraulic pump circuits. The main relief valve protects the system from dangerous overpressure conditions while allowing the ECU to modulate hydraulic output based on operational demands. Without proper solenoid function, you risk uncontrolled pressure spikes, reduced fuel efficiency, and potential catastrophic hydraulic component failure.

Common Symptoms

When Code 1244-5 is active on your R805LC-7, operators typically experience:

• Warning light illumination on the instrument cluster, often accompanied by a hydraulic system malfunction indicator
• Reduced hydraulic power or inconsistent performance during digging, lifting, or swing operations
• Intermittent loss of hydraulic functions, particularly under heavy load conditions when pressure regulation is most critical
• Erratic engine RPM response as the ECU attempts to compensate for pressure regulation failures
• Audible pressure relief valve cycling or unusual hydraulic pump noise during operation

Potential Causes

The most common technical causes for this fault code on used R805LC-7 excavators include:

• Failed main relief valve solenoid due to internal coil breakage or winding short (common after 8,000+ operating hours)
• Damaged or corroded wiring harness between the ECU and solenoid—check the harness routing near the main control valve where vibration and heat exposure cause insulation breakdown
• Connector corrosion or moisture intrusion at the solenoid connector (particularly on machines operated in wet/humid conditions)
• ECU internal driver circuit failure preventing proper current output to the solenoid
• Broken or disconnected ground connection specific to the hydraulic control circuit
• Previous repair damage to wire splices or harness sections near the engine-to-valve routing path

How to Troubleshoot and Fix Code 1244-5

Step 1: Initial Visual Inspection Begin by locating the main relief valve solenoid on the main control valve assembly (typically mounted on the right side of the excavator's center section). Disconnect the electrical connector and thoroughly inspect for corrosion, bent pins, or moisture. On used excavators, these connectors often show green corrosion or oil contamination. Clean with electrical contact cleaner and ensure the seal is intact.

Step 2: Solenoid Resistance Test Using a digital multimeter (DMM), measure the resistance across the solenoid terminals. The specification for the R805LC-7 main relief solenoid is typically 3-7 ohms at room temperature. An open circuit (infinite resistance) confirms solenoid coil failure. If resistance is within spec, check for short to ground by measuring from each terminal to the solenoid body (should read infinite resistance).

Step 3: Wiring Harness Continuity and Voltage Check With the connector still disconnected, trace the wiring harness from the solenoid back toward the ECU. Focus on areas where the harness passes through metal brackets or near heat sources—these are common rub-through points on used machines. Check for continuity from the ECU connector pins to the solenoid connector (should be less than 1 ohm). With ignition on and engine off, verify the ECU is supplying proper voltage (typically 12-24V depending on circuit design) to the solenoid circuit using your multimeter.

Step 4: Advanced Diagnostics with Manufacturer Software Connect Hyundai Hi-MATE diagnostic software or an equivalent dealer-level scan tool. Monitor live solenoid current values while commanding the solenoid on/off. Normal operating current should be 0.5-2.0 amps when energized. If the ECU commands activation but current remains at zero, the issue is in the wiring or solenoid. If current spikes abnormally high, suspect a partial short within the solenoid coil.

Step 5: Component Replacement and Verification For used excavators, if harness damage is found, replace the affected section rather than attempting field splices, as vibration will cause repeat failures. Replace the main relief valve solenoid if resistance or current tests fail. After replacement, clear fault codes, operate the machine through full hydraulic cycles, and verify the code does not return. Check hydraulic system pressure with a test gauge to confirm the relief valve is functioning at specification (typically 320-350 bar for the R805LC-7).

---

Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Hyundai service manual for your specific machine serial number, and consider professional diagnostic assistance for complex electrical or hydraulic system repairs. Improper repairs may result in equipment damage or safety hazards.