Steve writes by email: “A few weeks ago, I was out of town with my 2011 Honda Odyssey when the traction control system light came on, which is labeled VSA. I checked the owner’s manual and it appeared not to be a crisis since it was summer and I wouldn’t even hit any rain for the trip home. The engine operated normally for the 230-mile trip home. My repair shop checked the code and the problem was a bad spark plug. They replaced the plugs and the warning light went away. The car had about 130,000 miles on it when this happened; the plugs had been replaced at about 100,000 miles, plus all the coils replaced at about 125,000 miles. I don’t get the connection between the spark plugs and the traction control system. I hope you can help.”
My guess is that a misfire code was set and caused the VSA system to turn off because of an “engine power” related issue. I can’t find anything in service information that says the VSA will be disabled with a misfire, but the exact same thing happens if there are other engine-related problems. It seems the powertrain control module (PCM) monitors engine operating conditions and disables the VSA when it detects an abnormality. There have been reports of issues with some Odyssey engines with sticking piston rings. This causes oil consumption issues and misfires due to fouled plugs. My concern for this particular vehicle is that it has piston ring problems – resulting in misfires, plugs, coils – and is probably using oil. Honda has issued a technical service bulletin 13-081 that gives more details.