What is Case CX220C Fault Code 7246?

Fault Code 7246 on the Case CX220C excavator indicates a malfunction in the Boom Down Solenoid Circuit, specifically detecting an open circuit or abnormal electrical resistance in the solenoid valve control system. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects that the electrical signal to the boom down solenoid valve is interrupted or outside the expected voltage range.

This code directly affects the hydraulic pilot control system that governs boom lowering operations. The boom down solenoid is a critical electro-hydraulic component that modulates hydraulic oil flow to the boom cylinder during lowering functions. When this circuit fails, the ECM cannot properly command the solenoid, compromising machine control and potentially creating unsafe operating conditions. For used CX220C excavators, this code often signals age-related electrical degradation rather than catastrophic component failure.

Common Symptoms

• Intermittent or complete loss of boom down function while other hydraulic operations remain normal
• Boom control becomes erratic or unresponsive when attempting lowering operations
• Warning indicator light illuminated on the instrument cluster with reduced machine performance
• ECM may enter derate mode, limiting engine RPM or hydraulic system pressure as a protective measure
• Unusual delay or "jerking" motion when initiating boom lowering commands

Potential Causes

The most common technical causes for Code 7246 on used Case CX220C excavators include:

• Damaged or corroded wiring harness at known rub points near the boom base pivot and along the upper structure frame rails
• Failed boom down solenoid valve coil due to internal winding breakdown (resistance typically reads open circuit above 100 ohms or infinite)
• Corroded or loose electrical connectors at the solenoid valve connection point, especially on machines with high-hour exposure to moisture
• Chafed wiring insulation where harnesses contact metal edges during boom articulation cycles
• ECM internal driver circuit failure (less common, but possible on excavators exceeding 8,000 operating hours)
• Voltage supply issues from the main power distribution harness feeding the solenoid circuit

How to Troubleshoot and Fix Code 7246

Step 1: Visual Inspection and Connector Check Begin by performing a thorough visual inspection of the wiring harness routing from the ECM to the boom down solenoid valve. On used excavators, pay special attention to harness sections near the boom foot pin and swing bearing area where repetitive movement causes wear. Disconnect the solenoid connector and inspect for corrosion, bent pins, or moisture intrusion. Clean contacts with electrical contact cleaner and dielectric grease.

Step 2: Solenoid Resistance Testing Using a quality digital multimeter, measure the resistance across the boom down solenoid coil terminals with the connector disconnected. Typical specification for Case solenoids ranges from 8-15 ohms. A reading of infinite resistance (open circuit) confirms solenoid coil failure. Also check for continuity between each terminal and ground—any continuity indicates internal short to case.

Step 3: Circuit Voltage and Harness Continuity With ignition on and connector still disconnected, measure voltage at the harness-side connector. You should see battery voltage (approximately 12-14V) on the power supply wire. Check continuity from the ECM connector to the solenoid connector on both power and ground circuits. Resistance should be less than 5 ohms for the entire circuit path.

Step 4: Repair or Replace Components If wiring shows damage at rub points (common on machines with 5,000+ hours), repair using properly-sized marine-grade wire and heat-shrink connectors, then reroute with protective loom and secure with new zip ties. Replace the solenoid valve assembly if coil resistance is out of specification. For persistent codes after component replacement, ECM reprogramming or replacement may be necessary using Case Service Advisor diagnostic software.

Critical Note for Used Equipment: Before ordering expensive replacement parts, always address basic maintenance issues first—corroded grounds, worn harness grommets, and contaminated connectors account for over 60% of electrical fault codes on older excavators.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the official Case service manual for your specific serial number range and seek qualified technician assistance for complex electrical diagnostics or hydraulic system repairs.