I have a 2010 Acadia with 113000 miles on it. I had an issue with the gas cap not sealing, replaced gas cap then the next time I filled it up it wouldn't start ( never did that prior to replacing the cap) I took it in the shop (GMC dealership) they said it was the purge valve, replaced it for $250.00.. Drove it off the lot and three check engine light came back on..took it back..now it has 2 new fault codes that were not there when I picked it up...codes are P0008 & P0017.. These are generic codes that can be linked to timing issues... After being told it was going to cost over $3000 to fix I got a second opinion. The mechanic cleared out the codes and said if it was a timing issue I would have poor performance and rough idling... Which I knew and tried to tell the dealership but was blown off..the codes were cleared out and that lasted about 8 hours ( if it was timing issues they would've come back immediately) anyone have any suggestions as to what's going on or had similar issues?
P0008 Chevrolet 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.
P0017 Chevrolet Description
The Camshaft Position (CMP) actuator system enables the Engine Control Module (ECM) to change the timing of the camshafts while the engine is operating. The CMP actuator solenoid signal from the ECM is pulse width modulated (PWM). The ECM controls the CMP actuator solenoid duty cycle by controlling the amount of solenoid IN time. The CMP actuator solenoid controls the advancement or retardation of each camshaft. The CMP actuator solenoid control the oil flow that applies the pressure to advance or retard the camshafts.
Ignition voltage is supplied directly to the CMP actuator solenoid. The ECM controls the solenoid by grounding the control circuit with a solid state device called a driver. The ECM compares the camshaft position or the camshaft angle, to the position of the crankshaft. If the ECM detects a deviation between the camshaft position target and the crankshaft position, the code will set.