I am on autobeef looking for a solution to a stuck ignition lock that wont let me turn it out of off in my Impala. However, I did come across this issue, and maybe posting my solution will get the good Lord to fix my ignition

Since I noticed your posts are pretty recent, I'll let you know that I used to have issues with the PassLock in my 2005 impala randomly deciding not to start. The fix I stumbled across (partly on Internet info) was that if I always fill my tank up, I don't have the problem. As crazy as it sounds with gas prices fluctuating, I'm serious. I used to fill up half a tank at a time. Once it dropped to about 1/4 tank, the passlock/no start issue would begin. Once I consistently went from under 1/4 tank to full a the pump, it stopped. No problems for at least a year now.

Fourth occurrence in past two months, except this time it was just after the dealer called me earlier yesterday and said the massive shutdown problem (my third occurrence) was fixed and I could come pick up the car. I was leaving work on the way to pickup the car at the dealership when the dealer called me back and said to wait because the car will not start when they tried to move it up into the customer pickup area. The next day the dealer then replaced the ignition switch again (2nd ignition switch within a month). The dealer also stated that after testing the car, a �code� came up indicating that an internal transmission switch had a fault code (I asked was this the safety interlock switch that prevent the car from starting if the transmission is in gear and the Service representative stated yes). The Service Representative then stated the technician did not want to release the car until the problem occurred again. He also stated they did not want to replace this internal transmission part until the failure code occurred again because of the complexity of R/R the transmission. So now the car and I await for the final fix from the dealer (the car is still in today at the dealership awaiting for another mysterious code to flash across its diagnostics tool scanner) and with only two months and 4,000 miles to go for the cars warranty to expire, I hope they have found the problem once in for all this time.

I should also note that during the third and fourth occurrence, the radio would flash a message �CAL ERR� which I assume is Calibration Error. Also during the massive electronic shutdown, my headlights interior lights radio AC and power windows did work (this led the dealer to be confident that the problem was in the body control module). I also asked if the shop had any other troubleshoot tools such as oscilloscopes to watch the wave patterns he said yes but indicated they did not know how to use them (I have worked similar problems before on F-16 fighter planes, back in an Air Force Depot and Intermediate Level Repair Shop - I wonder if the big boys - Chevrolet - Ford - Chrysler excreta have this troubleshooting capability somewhere?)