On the 2008 Cadillac STS, the P0008 is “Engine Position System Performance Bank 1”. The engine control module (ECM) tests for a misalignment between both camshafts on one bank of the engine and 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 this DTC if both learned values for one bank of the engine are exceeding a calibrated threshold in the same direction. Unfortunately, the 3.6L engines are very well known for this issue. More times than not, this comes down to being a problem with the Timing Chain. There is actually a Technical Service Bulletin (# PIP3423K) issued by Cadillac on this issue :
-If the above concern is present, check for loose timing chains or tensioners.
-If after following diagnostics the root cause is not found, the following may be helpful.
-The reluctor for the crankshaft sensor pressed on the crankshaft may have moved.
-If the reluctor has moved then replace crankshaft.
Does your vehicle have a similar problem? Get connected to a Live Q&A session with a certified Auto Mechanic and get your answers on this problem now!