What is Case CX220C Fault Code 1113?

Fault Code 1113 on a Case CX220C excavator indicates an Intake Manifold Pressure (Boost Pressure) Sensor Circuit High Voltage condition. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects an abnormally high voltage signal from the intake manifold pressure sensor, typically exceeding 4.5-4.8 volts for more than 2 seconds.

The intake manifold pressure sensor monitors the air pressure in the intake manifold after the turbocharger compresses it. This data is critical for the ECM to calculate proper fuel injection timing and quantity. On the CX220C's Isuzu engine, accurate boost pressure readings ensure optimal combustion efficiency, power output, and emissions compliance. When this sensor circuit reads high, the ECM cannot properly manage air-fuel ratios, potentially causing performance degradation or engine protection modes.

Common Symptoms

When Code 1113 is active on your Case CX220C, you may experience:

• Check Engine Light or malfunction indicator illuminated on the instrument cluster
• Noticeable power loss or reduced engine performance, especially under heavy load conditions
• Engine derate mode activated, limiting maximum RPM to protect the engine
• Black smoke from the exhaust due to incorrect fuel-to-air mixture calculations
• Poor throttle response or hesitation during acceleration

Potential Causes

The most common technical causes for Code 1113 on used CX220C excavators include:

• Open circuit or damaged wiring in the sensor harness, particularly near the turbocharger where heat and vibration cause insulation breakdown
• Failed intake manifold pressure sensor with internal short circuit (common after 5,000+ operating hours)
• Corroded or loose connector pins at the sensor or ECM connection points
• Chafed wiring harness rubbing against engine components or frame rails—a known issue on CX220C models near the fuel filter bracket
• ECM internal fault (rare, but possible on machines with 8,000+ hours)
• Faulty 5-volt reference supply from the ECM affecting multiple sensors simultaneously

How to Troubleshoot and Fix Code 1113

Step 1: Visual Inspection Begin by inspecting the intake manifold pressure sensor located on the intake manifold near the turbocharger outlet. Check for physical damage, oil contamination, or loose mounting. Examine the wiring harness from sensor to ECM for visible damage, particularly where it passes near hot exhaust components or sharp metal edges—common wear points on used excavators.

Step 2: Electrical Testing Disconnect the sensor connector and use a digital multimeter to check the sensor's resistance. With the key off, measure resistance between the signal pin and ground—it should read approximately 150-250 ohms (consult your service manual for exact specifications). Next, check for supply voltage at the connector with ignition on: you should see approximately 5 volts on the reference wire.

Step 3: Circuit Continuity Check Disconnect both the sensor and the ECM connector. Test continuity between the sensor harness plug and ECM pins using a wiring diagram. Resistance should be less than 5 ohms. Check for shorts to voltage by measuring between each wire and battery positive—infinite resistance indicates no short. On used machines, pay special attention to connector terminals for corrosion or bent pins, which frequently cause high resistance issues.

Step 4: Component Replacement If wiring tests pass, replace the intake manifold pressure sensor with a genuine Case/Isuzu part or quality aftermarket equivalent. After installation, clear codes using Case diagnostic software or a compatible scan tool, then perform a test run under load to verify the repair.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Case service manual for your specific serial number and consider professional diagnosis for complex electrical issues or if you're unfamiliar with excavator systems.