Case Excavator Fault Code 0107: Complete Diagnostic Guide

What is Case Fault Code 0107?

Fault Code 0107 indicates a Barometric Pressure Sensor Circuit Low Voltage condition. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects an abnormally low voltage signal from the barometric pressure sensor circuit, typically below 0.5 volts for more than 2 seconds during engine operation.

The barometric pressure sensor plays a critical role in Case excavators by measuring atmospheric pressure to help the ECM calculate proper air-fuel ratios and optimize engine performance at varying altitudes. When this sensor circuit fails, the ECM cannot accurately compensate for altitude changes, directly impacting combustion efficiency, turbocharger boost control, and overall engine power output. In used excavators, this malfunction often leads to reduced productivity and increased fuel consumption.

Common Symptoms

When Code 0107 is active, operators typically experience:

• Check Engine Light or Malfunction Indicator Lamp (MIL) illuminated on the instrument cluster
• Noticeable loss of engine power or reduced throttle response, especially at higher elevations
• Hard starting conditions or rough idle, particularly in cold weather
• Increased black or gray exhaust smoke due to improper fuel mixture calculations
• DEF (Diesel Exhaust Fluid) system errors on newer models, as emissions calculations rely on accurate atmospheric pressure data

Potential Causes

The most common technical causes for Code 0107 in Case excavators include:

• Damaged or corroded wiring harness between the barometric pressure sensor and ECM (extremely common in used machines due to engine vibration and heat exposure)
• Failed barometric pressure sensor with internal short circuit or contamination
• Poor electrical connections at sensor connector pins, often caused by moisture intrusion or corrosion
• Chafed wiring at known rub points near the valve cover or along the harness routing behind the fuel filter assembly
• ECM internal fault (rare, but possible in high-hour machines)
• Low system voltage from weak batteries or failing alternator affecting sensor power supply

How to Troubleshoot and Fix Code 0107

Step 1: Visual Inspection Begin with a thorough physical inspection of the barometric pressure sensor (typically located on or near the intake manifold or ECM housing). Check the sensor connector for bent pins, corrosion, or moisture. Inspect the entire wiring harness from sensor to ECM for obvious damage, especially at areas where the harness contacts frame components or experiences heat exposure.

Step 2: Electrical Testing Using a digital multimeter (DMM), disconnect the sensor and measure resistance between the sensor signal pin and ground—specification typically ranges between 1,000-3,000 ohms (consult your specific Case service manual). Check supply voltage at the sensor connector with ignition ON/engine OFF; you should see approximately 5 volts on the reference voltage wire. Measure circuit continuity from sensor connector back to ECM pins.

Step 3: Sensor Replacement and Verification If voltage supply checks good but sensor resistance is out of specification, replace the barometric pressure sensor with a genuine Case or OEM-equivalent part. For used excavators, always apply dielectric grease to connector pins during reassembly to prevent future corrosion. After replacement, clear codes using Case diagnostic software (ServiceMaster or compatible scan tool) and perform a test run under load to verify proper sensor operation and confirm no code recurrence.

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Disclaimer: This guide provides general diagnostic procedures for Case excavators. Always consult your specific machine's service manual and safety protocols. If you're uncomfortable performing electrical diagnostics, contact a certified Case technician or qualified heavy equipment mechanic for professional assistance.