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I’m a auto mechanic repairing a 2010 Buick LaCrosse. I get the following codes:
P0014-00 Exhaust Camshaft Position System Performance Bank 1 Current
P0017-00 Crankshaft Position - Exhaust Camshaft Position Not Plausible Bank 1 Current
P0300-00 Engine Misfire Detected Not Run
P0420-00 Catalyst System Low Efficiency Bank 1 Not Run
P0430-00 Catalyst System Low Efficiency Bank 2 Not Run
P0442-00 Evaporative Emission (EVAP) System Small Leak Detected Not Run
P0451-00 Fuel Tank Pressure Sensor Performance Not Run
P0454-00 Fuel Tank Pressure Sensor Circuit Intermittent Not Run
P0464-00 Fuel Level Sensor Circuit Intermittent Not Run
P050D-00 Cold Start Rough Idle Not Run
P162B-00 Remote Vehicle Speed Limiting Signal Message Counter Incorrect Not Run
P2135-00 Throttle Position Sensors 1-2 Not Plausible Current
Timing and Performance Issues (P0014, P0017, P0300) These codes focus on Bank 1 (the firewall side on the 3.0L/3.6L V6). Stretched Timing Chains: The P0017 (Crank/Cam correlation) paired with P0014 is a classic sign of stretched timing chains, a frequent failure point for this GM engine platform. VVT Solenoid Failure: P0014 specifically indicates the exhaust camshaft is over-advanced. Before condemning the chains, inspect the Bank 1 Exhaust Variable Valve Timing (VVT) Solenoid for sludge or electrical failure. Oil Quality: Low oil level or dirty oil can prevent the VVT solenoids from controlling the cam phasers correctly, triggering these codes.
Sensor Circuit & EVAP Issues (P0451, P0454, P0464, P162B) The fact that you have “Intermittent” or “Performance” codes for the Fuel Tank Pressure Sensor, Fuel Level Sensor, and Speed Limiting signal suggests a shared electrical fault. Wiring Harness Rub: Check the wiring harness near the rear of the engine or where it runs toward the fuel tank. A rubbed-through harness can short the 5V reference circuit shared by these sensors. 5V Reference Circuit: If one sensor (like the Fuel Tank Pressure sensor) shorts internally, it can pull down the entire 5V reference line, causing multiple unrelated sensor codes (P0451, P0454, P2135).
Throttle & Idle Issues (P2135, P050D) Throttle Body: P2135 indicates a voltage correlation issue between Throttle Position Sensors 1 and 2. This often puts the car in “Reduced Engine Power” mode. Inspect the throttle body connector for corrosion or broken wires. Rough Cold Start: P050D is usually a secondary symptom of the timing issues or the throttle body fault mentioned above.
Catalyst Efficiency (P0420, P0430) Clogged Converters: These codes mean the catalytic converters are no longer cleaning the exhaust efficiently. On high-mileage LaCrosse models, persistent misfires (P0300) or rich conditions from timing issues often destroy the catalysts.