Possible causes

– Engine mechanical problems
– Incorrect timing chain
– Stretched timing chain
– Failed camshaft actuator or actuator solenoid

Tech notes

There is a factory service bulletin for the following GMC models:

2007-2008 GMC Acadia

The service bulletin suggest replacing the primary drive and both secondary drive timing chains. Contact your GMC dealer for more information. The repair could still be cover under factory warranty.

When is the code detected?

The ECM detects that both camshafts on either bank of the engine are mis-aligned with the crankshaft for more than 4 seconds or a cumulative of 50 seconds.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0008 GMC Description

The Engine Control Module (ECM) monitors the position of both camshafts and the crankshaft. The ECM performs a test for misalignment between both camshafts on one bank of the engine and the crankshaft. During the test the ECM learns the position of the camshafts and the crankshaft. While the engine is idling, the ECM compares the position of both the camshafts and the crankshaft with the learned value. The ECM will set the P0008 code if both learned values for one bank of the engine are exceeding a calibrated threshold in the same direction.

GMC Technical Service Bulletins for P0008 code