mfinksr Report post Posted February 16, 2012 I bought a 2008 Enclave, mainly because it was towable. And from the first trip, the Check Engine Light comes on after a few tow cycles. I took it to the dealer where they checked the codes and said a "cannister" needed replaced, which they did. Next trip, same thing, same code, new cannister. This went on every time we took the coach out. Finally, the same Service Writer decided there must be something else wrong. After a deeper trouble shooting they replaces the cannister and the wiring bundle that connects it to the computer. Well guess what happened the next trip. Right, "Check Engine Light". This time the Service Writer called Buick engineering in Lansing Michigan. The Engineer replied, "Yeah, that's what the Buicks do. Have the customer get a Code reader and he can reset the light." This did not seem like a reasonable thing to do, because I would never know it I would be resetting an invalid code or if there was a real fault that needed attention. Now, in the 2012 Towing Guide from FMCA, the procedure for all GM Crossovers requires pulling 2 fuses, the 15-amp ECM fuse and the 50-amp BATT 1 fuse. Previously, only the 50-amp BATT 1 fuse was pulled. Will this keep the invalid Check Engine Light from illuminating or is it totally unrelated? (P.S.: The 2012 DINGY TOWING GUIDE from Motorhome Magazine does not mention the 15-amp ECM fuse,) Share this post Link to post Share on other sites
dickandlois Report post Posted February 17, 2012 Mfink, Pulling the ECM power fuse should keep the check engine code from setting. The one thing you have to remember, that by doing this and you live in a state the has rigid inspection requirements, you will need to drive a number of miles before it will pass. I would think that the garage could give you the code number and if your check engine light comes on an you have someone read the code fault, you will know if its the same old problem. Have the parts store reset it. a copy of the repair orders from your service center should re leave any concerns they might have. Many Parts outlets have code readers now days and will read them for free,hoping you will by some parts. I travel with a code reader, because I have a truck that sets the check engine light from time to time. The problem is the temperature the O2 sender runs at. If I make a number of short trips sometimes it sends a code. Then again it my not come on for a year. always the same code. Hope this helps. R.M. Share this post Link to post Share on other sites
mfinksr Report post Posted February 17, 2012 R.M., Thanks for the info. I do know the code, but it is fairly generic and it does have emisions implications. The dealer has repeatedly replaced the "cannister" based on the code. Replacing the cannister is not cheap. So just clearing the code seems to defeat the purpose. And since Buick knows of this problem, they should be coming forward with a fix for it. It could be as simple as pulling the ECM fuse or a minor computer program change. And it only happens after several towing cycles, usually around 5. Share this post Link to post Share on other sites
dickandlois Report post Posted March 2, 2012 Been thinking about this issue in the back of my mind. You mention, after about 5 towing cycles. How far do you run on each cycle/trip? and is there an increase in temperature that happens each time the check engine light comes on? You mentioned the garage has changed the canister when the code comes up. Thinking that the code is related to the fuel evaporation sensing circuit. I have no information regarding the purge cycling interval programed into the ECM. Thought is that if there is power to the ECM even when being towed,along with other data being collected,say wheel rotation signals would be present and a purge cycle is initiated and the purge valve is opened ( valve is powered from the ECM), the integrity of the fuel vapor recovery system fails,Because the vacuum level detected in the system is missing or does not change. Then a check engine code would be set. Emission system failed. A little like when we forget to tighten the gas cap, or in my case,should I trigger the low fuel light and leave the engine running while fueling. The light stays on until I turn off the engine. Then the fuel level sender voltage in high enough to reset the ECM and the light is off when I start the engine again. The ECM can not reset the low fuel code even if I drive for hrs. Stop the engine and away goes the low fuel indicator, a piece of missing code in the software. If the light never comes on then I can add fuel with the truck running and no light. Leave the gas cap loose and the check engine code will come on. Just some thoughts from outside the box. R.M. Share this post Link to post Share on other sites
