I tried the deflation method to retrain my sensors yesterday and it was a big failure. The horn beeped on the first tire but nothing on the second and when I looked at the dash it said "Service Tire Pressure Monitoring System". I tried it a second time and I couldn't even get it to beep for the first tire. All the readings were solid dashes. I had to take it to the dealer and get them to reset it with the tool.