🚨 Diagnostic Profile
Vehicle Make: BUICK
Technical Description: Injector Control Circuit Intermittent
This fault indicates that the Engine Control Module (ECM) is detecting an inconsistent or intermittent electrical signal on one or more fuel injector control circuits. This can cause rough idle, misfires, hesitation, or intermittent loss of power, and is commonly triggered by wiring harness chafing, corroded connector pins, or a failing injector driver inside the ECM.
🚨 Repair Difficulty Tier
Difficulty Rating: Intermediate
This repair requires a digital multimeter, a scan tool capable of reading live injector pulse data, and a solid understanding of wiring diagrams. While not as high-liability as airbag or restraint system work, intermittent electrical faults can be time-consuming to isolate and may require wiggle-testing harnesses under load. No module programming is typically required unless the ECM itself is replaced.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
Begin by visually inspecting the engine harness, particularly near the valve cover and injector connectors, for signs of chafing, melted insulation, or corrosion. Check all injector harness connectors for loose or spread pins, and inspect the ECM connector for moisture intrusion or corroded terminals. Pay close attention to any areas where the harness may rub against brackets or the engine block.
Step 2: Diagnostic Verification
Connect a scan tool and monitor live injector control data while performing a wiggle test on the harness to recreate the intermittent fault. Use a digital multimeter in conjunction with a breakout box (if available) to check injector control circuit resistance and voltage drop across the harness and connectors. Compare resistance values to OEM specifications (typically 12-16 ohms for most Buick injectors) and check for voltage drop exceeding 0.2V under load. Freeze frame data should also be reviewed to identify conditions present when the code was triggered (e.g., engine temperature, RPM, load).
Step 3: Resolution & Reset Process
If a damaged harness section or connector is found, repair or replace the affected wiring using OEM-spec connectors and weatherproof splicing techniques. If the injector itself tests out of specification, replace the faulty injector using the correct torque sequence for the fuel rail. After repairs, clear the diagnostic trouble codes using a scan tool, perform a full ECM relearn/idle relearn procedure if applicable, and conduct a test drive while monitoring live data to confirm the intermittent fault does not return.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: Fuel injector (if faulty), injector harness connector/pigtail repair kit, dielectric grease, OEM-spec scan tool (e.g., GM Tech2 or equivalent aftermarket scanner with bi-directional control)
Average Component Price: $45–$150 per injector (OEM), $15–$40 for harness repair kits/connectors
Estimated Labor Hours: 1.5–3.0 hours for diagnosis and circuit repair; add 0.5–1.0 hour per injector if replacement is required