Our 2004 just came out of the repair shop where, after about two weeks of troubleshooting, they found a broken wire, in the insulation, next to the main computer. This was causing the fuel pump to not run. Now the original key, that has worked for years, will no longer turn the lock cylinder. The spare aftermarket key that we use occasionally, and left when we dropped the car off at the independent repair shop, works fine, but only if I push in on it, against a small resistance, before I turn it. This works every time. What could have happened that would cause the "old" key to suddenly not work anymore?