What is Case CX210C Fault Code 7248?

Fault Code 7248 on the Case CX210C excavator indicates a malfunction in the aftertreatment fuel injector circuit, specifically reporting an open circuit or electrical fault in the diesel exhaust fluid (DEF) dosing system. This code is generated by the electronic control module (ECM) when it detects insufficient current flow or a complete break in the wiring harness that controls the SCR (Selective Catalytic Reduction) fuel injector.

This fault is critical because the aftertreatment system is essential for meeting emissions standards and maintaining engine performance. When this circuit fails, the excavator may enter derate mode, limiting productivity on the jobsite. For used CX210C machines, this code often appears due to age-related harness degradation or connector corrosion rather than actual injector failure.

Common Symptoms

When fault code 7248 is active, operators typically experience:

• Amber or red warning lights illuminated on the instrument cluster, specifically the emissions system indicator
• Engine power derate after a predetermined time period, reducing available horsepower by 25-40%
• Increased exhaust temperatures as the aftertreatment system fails to properly reduce NOx emissions
• Poor fuel economy due to the ECM attempting to compensate for the malfunctioning DEF dosing system
• Stored fault codes that may include related aftertreatment system errors alongside 7248

Potential Causes

The most common technical reasons for code 7248 on used CX210C excavators include:

• Damaged wiring harness near the engine mount or along the frame rail where vibration causes wire chafing
• Corroded or loose connector pins at the aftertreatment fuel injector plug, especially on machines operated in wet or salty environments
• Failed DEF injector solenoid due to crystallized DEF deposits blocking the nozzle or internal electrical failure
• ECM internal driver circuit failure, though less common than external wiring issues
• Broken or pinched wires at harness routing points near the aftertreatment canister

How to Troubleshoot and Fix Code 7248

Step 1: Visual Inspection Begin by thoroughly inspecting the wiring harness from the ECM to the aftertreatment fuel injector. On used excavators, pay special attention to areas where the harness routes near moving components or sharp edges. Look for abraded insulation, exposed copper, or evidence of harness repairs.

Step 2: Connector and Pin Testing Disconnect the injector connector and inspect for bent pins, corrosion (green/white residue), or moisture intrusion. Clean contacts with electrical contact cleaner and apply dielectric grease. Using a digital multimeter, check for continuity between the ECM connector pins and the injector connector—you should see less than 5 ohms resistance on a good circuit.

Step 3: Injector Resistance Check With the connector still disconnected, measure the resistance across the injector terminals. The aftertreatment fuel injector should typically read between 2-6 ohms (consult Case service manual for exact specifications). An open circuit (infinite resistance) confirms injector failure.

Step 4: Power and Ground Verification Using your multimeter with the key on, verify the ECM is supplying voltage to the injector circuit (typically 12V when commanded). Check the ground circuit integrity by measuring voltage drop—anything above 0.5V indicates a poor ground connection requiring cleaning or replacement.

Step 5: Component Replacement If wiring and connections test properly, replace the aftertreatment fuel injector. For used machines, consider replacing the injector connector pigtail simultaneously, as these often fail together. After replacement, use Case diagnostic software to clear codes and perform an injector actuation test.

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Disclaimer: This guide provides general diagnostic information for Case CX210C excavators. Always consult the manufacturer's service manual and consider professional diagnosis for complex electrical issues. Improper repairs may cause additional damage or void warranties on used equipment.