Intake Camshaft Position Timing Over-Advanced (Bank 2)

Intake camshaft timing over-advanced on bank 2 is most often caused by dirty oil or a stuck variable valve timing (VVT/VTC) solenoid. Start with an oil and filter change using the correct viscosity — sludge is the #1 cause. If it persists, replace the bank 2 intake camshaft position actuator solenoid before suspecting the timing chain.

Bank 1 is always the bank containing cylinder number 1, and Bank 2 is the opposite head - which physical side that is depends on whether your engine sits transversely or longitudinally, so confirm it against the cylinder numbering diagram for your specific engine before buying a side-specific part. The code is most often dirty oil or a stuck intake VTC (variable timing control) solenoid, not the timing chain. Change the oil and filter with the correct grade first, then replace the bank 2 intake camshaft position / VTC solenoid. Only suspect the timing chain or VTC actuator (cam sprocket) if you hear a cold-start rattle that fades after a few seconds.

The 3.6L V6 is known for both VVT actuator solenoid sticking and timing chain stretch. Start with an oil change on the Dexos spec and replace the bank 2 intake cam actuator solenoid. Important: if there is a rattle on cold start or you also see P0008/P0016/P0017 (correlation codes), the timing chains and guides are the real fix -- the solenoid alone will not clear it. GM issued TSBs covering early-build 3.6L chain wear.

On the Cyclone V6, P0021 is usually a sticking variable cam timing (VCT) solenoid or a worn cam phaser, aggravated by extended oil-change intervals. Change the oil and replace the bank 2 intake VCT solenoid first. A persistent cold-start 'diesel-like' rattle points to a failed phaser, which is a bigger job -- do not just keep replacing solenoids if the rattle is present.