The first five codes all point to the same problem and it is very common on that engine. They are showing that you need to replace all of the timing chains and guides as well as test the VVT sprockets for correct motion. The issue is that GM changed to a thinner roller chain that wears very fast and once they set the codes you have you are on borrowed time before one or more of the timing chains fail and damages the engine to the point of replacement. The codes themselves are for a difference between the camshaft timing between each other and between the camshafts and the crankshaft positions. Basically the PCM reads the sensors and is seeing that the camshaft positions are out of time the equivalent of three teeth on the chain. That is the amount of difference compared to new that you can see using an oscilloscope on the cam and crank sensor signals. Usually between 2.5 and 3 tooth differences sets the cam/crank codes.
The last two codes also are an issue, they are both catalytic converter codes that say that both of the upstream converters are not working. It is possible that replacing the chains and running it a bit could clear those two codes as they may be set due to the random mixtures the timing chain and PCM are sending into the exhaust. It may also be that due to the mileage and the camshaft issues they are now damaged and need to be replaced.
If you search for GM 3.6 timing chain failures you will get a lot of information above what I covered along with multiple videos of the chains being replaced and engines where they were not replaced in time. While that is being done it is a good time to do the water pump as well. The image below shows the chain layout. There are a few special tools and a specific sequence to replacing them. The engine has to be removed from the vehicle (through the bottom with the cradle) and there are multiple items that need to come off and apart.
GM was covering these under the 11340C †Special Coverage Adjustment sheet. Basically a 10 year/120,000 mile period. So you still have some time to get it repaired under that.
Search special warranty #11340 the first item that shows as a pdf file is the one you want to read.
It will have the following text in it-
On some 2007 model year GMC Acadia and Saturn OUTLOOK; 2007-2009 model year Cadillac CTS, SRX, and STS; 2009 model year Buick Enclave, Chevrolet Traverse, GMC Acadia, and Saturn OUTLOOK vehicles that are equipped with a 2.8L/3.6L V6 engine (LP1/LY7/LLT), under certain driving conditions, and with the vehicle's original oil change intervals, the timing chain could wear prematurely and cause the illumination of the Service Engine Soon light.
Special Coverage Adjustment
This special coverage covers the condition described above for a period of 10 years or 120,000 miles (193,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.
Dealers are to replace the timing chain. If a customer brings their vehicle to the dealership and it is determined that the timing chain does not require replacement, dealers are to reprogram the ECM with updated software, if applicable. Refer to the Service Procedure contained in this bulletin to determine if reprogramming is required. The repairs will be made at no charge to the customer.
For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after February 17, 2012, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to February 17, 2012, must be submitted to the Service Contract provider.
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Tuesday, June 12th, 2018 AT 5:41 PM
