The Check Engine MIL may be illuminated on some 2016-2018 ATS, CT6, CTS; 2017-2018 LaCrosse, XT5; and 2018 Enclave, Regal, and Traverse models equipped with the 3.0L V6 engine (RPO LGW) or 3.6L V6 engine (RPO LGX, LFY) (Fig. 9) along with several possible drivability issues, such as hesitation or loss of power, after an auto stop/start event. In addition, camshaft position system performance DTCs P0011 (Intake Camshaft Position System Performance Bank 1), P0014 (Exhaust Camshaft Position System Performance), P0021 (Intake Camshaft Position System Performance Bank 2) and P0024 (Exhaust Camshaft Position System Performance Bank 2) may be set in history.
Fig. 9
The DTCs may all be set at the same time or may be set in pairs of phaser performance DTCs (P0011 and P0021 or P0014 and P0024). In some cases, single and triple phaser performance DTCs may be set (P0011 first and then P0021, P0014 and P0024).
These conditions and DTCs may be caused by a software anomaly that allows the “verify sync” status to not restart and reach full “sync” when the engine restarts during an auto stop/start event. In this case, the Engine Control Module (ECM) will report the actual cam positions as zero while it continues to command the actuators to move, resulting in engine roughness or drivability concerns along with the possibility of setting multiple cam phaser performance DTCs.
These cam phaser performance and resulting drivability conditions are currently being reviewed by GM engineering. If no other concerns are found, clear the DTCs and return the vehicle to the customer.
GM Engineering is currently evaluating this condition and working on a repair recommendation. For additional information, refer to #PIP5568E.
– Thanks to Bryan Salisbury
