This bulletin applies to a host of GM vehicles equipped with a 3.6L LY7, 3.6L LLT or 2.8L LP1 engine. Vehicle models are as follows:
2004-2012 Cadillac CTS SRX
2004-2012 Cadillac STS
2005-2012 Buick Lacrosse
2008-2012 Buick Enclave
2007-2012 GMC Acadia
2010-2012 Chevy Camaro
2008-2012 Chevy Equinox
2012 Chevy Impala
2008-2012 Chevy Malibu
2009-2012 Chevy Traverse
2007-2009 Pontiac G6
2008-2009 Pontiac G8, Torrent
2007-2010 Saturn Aura, Outlook
2008-2010 Saturn Vue
One or more of the following DTCs may be stored: P0016, P0017, P0018, P0019, P0008 or P0009. Initially check for loose timing chains or tensioners. If after following Si diagnostics the root cause is not found, consider that the crankshaft reluctor wheel may have moved. This would result in improper timing signals picked up by the crankshaft position sensor.
The rear crankshaft counterweight edge should be aligned with approximately 3 ½ teeth on the reluctor wheel. As an example, if the wide open gap between wheel teeth is aligned with the edge of the counterweight, the reluctor wheel has moved. If the wheel has moved on the crankshaft, the crankshaft must be removed and the reluctor wheel must be repositioned according to service manual specifications.
The specific procedure for removing and reinstalling the reluctor wheel must be followed to avoid damaging the wheel. The alternative is to replace the crankshaft with a new unit that already has a reluctor wheel installed.
NOTE: An aftermarket company, Goodson Tools & Equipment, offers a specialty indexing tool designed for properly indexing and installing a reluctor wheel.
