🚨 Diagnostic Profile
Vehicle/Equipment Make: BUICK
Technical Description: Injector Control Circuit
This diagnostic code indicates a fault within the Injector Control Circuit, which governs the precise electrical signaling between the Engine Control Module (ECM) and the fuel injectors. Issues in this circuit typically manifest as rough idle, misfires, hard starting, or a complete failure of one or more cylinders to fire correctly. The root cause is often related to wiring harness damage, connector corrosion, a failing injector driver inside the ECM, or a faulty injector solenoid itself.
🚨 Repair Difficulty Tier
Difficulty Rating: [Intermediate]
This repair requires the use of a quality automotive scan tool capable of reading live data streams (Mode 06 or manufacturer-specific PIDs) and a digital multimeter to test resistance and voltage across the injector circuit. While not as high-risk as airbag or restraint system work, this repair does require intermediate electrical diagnostic knowledge to avoid misdiagnosing the ECM versus the wiring harness versus the injector itself. A DIY beginner may struggle without prior experience in circuit testing, but a home mechanic with multimeter experience can often handle the diagnostic phase.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
Begin by performing a visual inspection of the engine harness connectors leading to the fuel injectors. Look for signs of melted plastic, corrosion, or pushed-out terminal pins at the injector connector itself. Check the main engine harness for any chafing points where it may rub against the engine block or accessory brackets, as this is a common failure point on Buick V6 engines. Additionally, inspect the ground strap connections near the throttle body, as a poor ground can mimic injector circuit codes.
Step 2: Diagnostic Verification
Connect an OBD-II scan tool and retrieve freeze frame data to identify which specific cylinder or bank is affected. With the key on/engine off, use a digital multimeter to check for proper reference voltage (typically 12V) at the injector connector; a reading significantly lower indicates a wiring or power supply issue upstream. Next, disconnect the injector and measure the resistance across its terminals (typically between 11-18 ohms for most port-injected Buick engines, though GDI models vary); a reading of infinite resistance (open circuit) or 0 ohms (short circuit) confirms a bad injector. If resistance is within spec, perform a ‘noid light’ test to verify the ECM is actually pulsing the injector driver correctly.
Step 3: Resolution & Reset Process
If the injector resistance test fails, replace the faulty injector and always replace the corresponding O-rings to prevent vacuum or fuel leaks. If the wiring harness is found to be chafed or corroded, repair the segment using OEM-grade wire and heat-shrink butt connectors rather than simple electrical tape to ensure a weatherproof seal. Once the repair is complete, clear the Diagnostic Trouble Codes (DTCs) using the scan tool and perform an idle relearn or drive cycle to confirm the ECM registers the circuit as functioning correctly without the code resetting.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: OEM or OEM-equivalent Fuel Injector(s), Injector O-ring kit, Weatherproof wiring repair connectors, OBD-II Scan Tool with live data capability.
Average Component Price: $45 – $120 per injector (depending on engine type – naturally aspirated vs. turbocharged/GDI); Wiring harness repair kits typically range from $15 – $40.
Estimated Labor Hours: 1.5 to 2.5 hours for diagnostics and single injector replacement; add 0.5 hours per additional injector if multiple units require replacement simultaneously.