I bought my 06 DTS last May since then I have driven about 9K. The last three fill-ups have resulted in the check engine light coming on after about 70 mi. I then open and close the gas cap and after about 30 miles the light goes out. I called ONStar and had them run a diagnostic check the first time it happened and they told me it was an Oxygen sensor. I doubt it is an incorrect gas cap closing since it just started. Any suggestions.

Thanks
Frank

 

Your car is not the only one I seen throwing a code with a full tank of fuel.
Although most of the time a car does fine with a full tank, that is one of reasons
you NEVER NEVER fill a tank to take a car for a SMOG TEST.

The computers are calibrated at something other than full, and are designed to issue
codes when the emissions are out of limits.

Maybe is time i complete a write up on EMISSIONS.

There should be a code connected with the warning, ONSTAR is looking at the codes.
That code will help determine the problem, ask them what codes were displayed.


.

 

I will call Onstar and get the codes but what is puzzling is the fact that this is just starting and I've had the car since the end of May and took one 2500 mile trip and no codes. I'll keep you posted.

Frank

 

The saga continues. Took the car to the Dealer and they determined that it was a faulty oxygen sensor so they replaced it. The code was P1153 Bank 2. I picked the car up tonight and got exactly 1.4 miles from the dealership when the "check engine" light came on. This must be something else as it usually took 70 miles after a fill up for the light to come on and now it came on after only 34 miles. As the Service Dept had closed for the day I drove home (24 mi). I will call in the A.M. and see what they have to say after first starting the car and see if....................
Needless to say I'm not a happy camper.

Frank[>:]

 

Called Onstar this a.m for a diagnostic check and they confirmed that oxygen sensor was the problem. They contacted Dealer and I bought the car to them. After a short time Dlr confirmed that the new Sensor they installed the day before appeared to be "faulty" and they would install a new one the next day as the part was unavailable. So here is the skinny> I'm dealing with a Mega Dealer who sells GM, Ford and Honda products. One would think a Dealership of this size would have a sufficient parts inventory to servce their customers. So now it looks like it will take four days to correct this problem. It also begs the question why wasn't it checked the first time??? This is my first American car in many years as previous cars were Audi and Acura's. Problem free I might add. Yes I'm questioning the wisdom of my purchase but hopefully this will be the solution and happy motoring will be restored.

Frank

Ps I'm a retired Military Maintainence Officer and if we did this stuff to the aircraft under our responsibility..............
check ,recheck and check again was our mantra.

 

Had same issue. As soon as I replaced the gas cap, the problem went away. Quick and easy fix. Even though the old cap clicked, it wasn't sealing properly which set off the CheckEngine light.