09 traverse p0008

Messages
3,872
Location
southern mo
We tried to help this guy pass emissions at work. It's just not going to happen. Keeps throwing this code. On these is it almost always a stretched timing chain? Anybody have some knowledge on these engines ? Very surprised that it could be the chain it has 84,000 miles on it and does run good......
 
Messages
15,879
Location
NE,Ohio
DTC P0008: Engine Position System Performance Bank 1 Circuit/System Description: The engine Control Module (ECM) tests for a misalignment between both camshafts on one bank of the engine & 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 a DTC if both learned values for one bank of the engine are exceeding a calibrated threshold in the same direction. Conditions for running the DTC: - engine operating for > 50 seconds - engine coolant between 0-95 C (32-203 F) - calculated engine oil temp < 120 C (248 F) - the engine must accelerate such that the CMP actuator system is commanded from the park position to the phased position. This is considered a cam control cycle. There must be a minimum of 2 cam control cycles for at least 2.5 seconds each, in the phased position. - DTC 0008 run continuously once the above conditions are met, approx 600 seconds Conditions for setting the DTC: The ECM detects that both camshafts on either bank of the engine are mis-aligned with the crankshaft, greater than 6 degrees, for greater than 4 seconds or a cumulative of 30 seconds. Diagnostic Aids: The presence of DTC P0008 along with P0016, P0017, P0018 and P0019 indicates a possible condition with the primary timing chain and the alignment between both intermediate sprockets and the crankshaft. Or, the crankshaft reluctor wheel has moved and is no longer referenced to top dead center (TDC) Observe the scan tool CMP Desired, Actual, and Angle Variance parameters before a DTC sets. This may help to isolate whether a condition is specific to one camshaft, one bank, or caused by a condition with the primary crankshaft timing. Circuit / System Verification 1. Clear the DTCs with a scan tool 2. Allow the engine to reach the normal operating temperature. 3. Idle the engine for 10 minutes or until a DTC sets. Observe the DTC info with a scan tool, DTC 0008 should not be set. 4. Operate the vehicle within the "Conditions for Running the DTC" to verify the DTC does not reset. Circuit/System Testing 1. Inspect the timing chains and tensioners for excessive wear or misalignment - repair as necessary 2. Inspect the crankshaft reluctor wheel for being mis-positioned on the crankshaft - repair as necessary
 
Messages
17,501
Location
Clovis, CA
Originally Posted By: Rand
Conditions for setting the DTC: The ECM detects that both camshafts on either bank of the engine are mis-aligned with the crankshaft, greater than 6 degrees, for greater than 4 seconds or a cumulative of 30 seconds.
Does that mean the camshafts are out of time? Is that what it means?
 
Top