Possible causes – Dirty Oil– Low engine oil level– Faulty Exhaust Camshaft Position Actuator Solenoid– Exhaust Camshaft Position Actuator Solenoid harness is open or shorted– Exhaust Camshaft Position Actuator Solenoid circuit poor electrical connection– Faulty Engine Control Module (ECM) Tech description There is a factory service bulletin for the following Hummer models: 2004-2009 Hummer H32004-2009…