The P0008 DTC code is generic, so that means it applies to all makes of vehicles. This source says it best:
The Engine Control Module (ECM) tests for misalignment between both camshafts on one bank of the engine & the crankshaft. The misalignment would be at an idler sprocket for either bank or at the crankshaft. Once the ECM learns the position of both camshafts on one bank of the engine, the ECM compares the learned values to a reference value. The ECM will set a DTC if both learned values for one bank of the engine are exceeding a calibrated threshold in the same direction.
Symptoms of a P0008 DTC may include:
•MIL (Malfunction indicator lamp) illumination
•Roughness while accelerating
•Poor fuel economy
•Decreased power
•Timing chain "noise"
Potential Causes
Potential causes of a P0008 code may include:
•Stretched timing chain
•Crankshaft reluctor wheel has moved and is no longer referenced to top dead center (TDC)
•Timing chain tensioner problem
Possible Solutions
If your vehicle is new enough that it still has powertrain warranty left, by all means let the dealer perform the fix. Generally, diagnosing and fixing this DTC will involve inspecting the timing chains and tensioners for excessive wear or misalignment, and inspecting the crank reluctor wheel for proper positioning. Then replacing parts as required.
General Motors has really had vehicle issues with this code, be glad that you don't own one
