Key and security system diagnostics are not that much different than driveability diagnostics.
In the 1980s, the only thing standing between a thief and starting a car was the lock’s tumbler. The thief could pick the lock or violently remove the lock’s tumbler with a slide hammer. Re-keying a car involved installing a new lock cylinder – this is not the case with most late-model vehicles.
Whether the customer brings in the vehicle with a TPMS light triggered, or one triggers as a result of performing some tire service, not being able to turn off the MIL can sometimes cause headaches for shops. Here are a few commonly overlooked issues that could be triggering a warning light.