🚨 Diagnostic Profile
Vehicle Make: BUICK
Code/System: Intake Camshaft Position (CMP) Sensor System Performance
Description: This diagnostic trouble code indicates that the Engine Control Module (ECM) has detected an irregularity in the signal pattern from the Intake Camshaft Position Sensor. This sensor works with the crankshaft position sensor to allow the ECM to properly time fuel injection and ignition spark, as well as control variable valve timing (VVT) solenoids. A ‘Performance’ designation specifically means the sensor is producing a signal, but that signal does not correlate correctly with expected engine speed and crankshaft data, often pointing to timing chain stretch, a failing VVT solenoid, or sensor degradation rather than a complete electrical failure.
🚨 Repair Difficulty Tier
Difficulty Rating: Intermediate
Summary: This repair falls into the Intermediate category. While replacing the sensor itself is often straightforward and accessible with basic hand tools, accurately diagnosing a ‘Performance’ code requires a capable scan tool to view live camshaft and crankshaft correlation data (Mode $06 or Enhanced Data). Additionally, verifying timing chain stretch or VVT solenoid function may require mechanical knowledge of the timing cover components. This is generally beyond basic DIY but does not require complex module programming or high-liability safety systems.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
Begin by visually inspecting the sensor’s wiring harness and connector for signs of chafing, corrosion, or disconnection near the intake camshaft sensor housing. Check for oil contamination at the connector, as oil intrusion is a common cause of signal interference in these circuits. Inspect the engine oil level and quality, as low or degraded oil can affect VVT solenoid performance, which may trigger a correlated camshaft performance code.
Step 2: Diagnostic Verification
Connect an OBD-II scan tool capable of reading enhanced manufacturer data (not just generic codes) to view live Camshaft/Crankshaft Correlation data. Compare the Intake Cam Sensor ‘B’ position against the crankshaft reference signal while idling and during a controlled rev-up. Using a digital multimeter, back-probe the sensor connector (key off) to verify the 5-volt reference signal and ground circuit integrity match OEM wiring diagram specifications. If equipped with Variable Valve Timing, command the VVT solenoid via a bi-directional scan tool to ensure it responds correctly to oil pressure actuation.
Step 3: Resolution & Reset Process
If wiring and solenoid tests pass but correlation remains erratic, replace the Intake Camshaft Position Sensor with an OEM-specified component. If diagnostics reveal timing chain stretch beyond factory tolerance, the timing chain, guides, and tensioner assembly must be replaced to restore correct cam-to-crank timing. After component replacement, clear the Diagnostic Trouble Codes (DTCs) using the scan tool and perform a drive cycle to confirm the Performance code does not return under normal driving conditions.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: Intake Camshaft Position Sensor, VVT Solenoid (if faulty), Timing Chain Kit (if stretch detected), OEM-level scan tool with bi-directional control capability.
Average Component Price: Camshaft Position Sensor: $40–$120. VVT Solenoid: $80–$200. Full Timing Chain Kit (if required): $300–$600 in parts alone.
Estimated Labor Hours: Sensor replacement and diagnostics: 0.5–1.5 labor hours. If timing chain component replacement is required due to correlation failure, labor hours increase significantly to approximately 4–8 hours depending on engine configuration and accessory removal needed for timing cover access.