What is Caterpillar Fault Code CID4267?

Caterpillar fault code CID4267 indicates a Cylinder #4 Injector Circuit High Voltage condition detected by the Engine Control Module (ECM). This diagnostic trouble code (DTC) is triggered when the ECM detects abnormally high voltage in the electrical circuit controlling the fuel injector for cylinder number four, typically exceeding manufacturer-specified parameters during injector operation.

This code is critical for Caterpillar diesel engines because precise injector control directly affects combustion efficiency, fuel economy, and emissions compliance. When CID4267 appears, the ECM may implement power derate strategies to protect the engine from potential damage caused by improper fuel delivery or electrical faults. In used excavators, this fault often results from degraded wiring harnesses, corroded connectors, or injector solenoid failures common in high-hour machines.

Common Symptoms

• Check Engine Light or warning lamp illuminated on the instrument cluster
• Engine power derate or limp mode activation, resulting in reduced hydraulic performance
• Rough idle or misfiring specifically from cylinder #4, creating noticeable vibration
• Increased fuel consumption or black smoke from exhaust during operation
• Stored fault codes in ECM memory even after engine restart

Potential Causes

The most common technical causes for CID4267 in used Caterpillar excavators include:

• Damaged injector wiring harness with insulation wear at valve cover rub points (extremely common in older machines)
• Failed fuel injector solenoid in cylinder #4 creating internal short or open circuit
• Corroded or loose electrical connectors at the injector or ECM harness connections
• Faulty ECM injector driver circuit (less common but possible in high-hour units)
• Water intrusion into injector connectors from damaged valve cover seals
• Chafed wires rubbing against engine components due to improper harness routing or missing clips

How to Troubleshoot and Fix Code CID4267

Step 1: Visual Inspection Begin with a thorough inspection of the cylinder #4 injector harness from the ECM to the injector connector. Check for obvious damage, abrasion points where the harness contacts the valve cover or engine block, and examine connector pins for corrosion or bent terminals. On used excavators, pay special attention to harness securing clips that may have broken over time.

Step 2: Electrical Testing Using a digital multimeter, disconnect the injector connector and measure resistance across the injector solenoid terminals (typically 0.3-0.7 ohms for most Cat injectors). Check for short to voltage by measuring between each injector terminal and ground with the harness connected but injector disconnected—any voltage present indicates wiring fault.

Step 3: Connector and Harness Repair Clean all connector contacts with electrical contact cleaner and dielectric grease. Inspect the injector harness for internal wire breaks by performing a wiggle test while monitoring resistance. Replace damaged sections or the entire harness if multiple wear points exist—common in machines with 8,000+ operating hours.

Step 4: Component Replacement If wiring tests pass, replace the cylinder #4 fuel injector after verifying part number compatibility. Clear codes using Caterpillar Electronic Technician (Cat ET) software and perform injector cutout tests to confirm proper operation.

Disclaimer: This guide provides general troubleshooting information. Always consult the specific service manual for your Caterpillar model and consider professional diagnostic services for complex electrical issues or injector calibration procedures.