Buick LaCrosse won't start after new key cut and relearn procedure on Buick LaCrosse

Some Buick LaCrosse owners report experiencing starting issues even after a new key has been cut and a relearn procedure has been performed. These problems may stem from a malfunctioning pass lock sensor in the ignition switch or lock cylinder housing, which can prevent the vehicle from starting. Additionally, a faulty theft deterrent module located near the ignition switch could also cause similar starting issues. In some instances, owners have identified a failing crank sensor as the underlying problem, particularly following a battery replacement or jump-start. It is crucial to ensure that the relearn procedure was executed correctly, especially if components like the PASS-Key III keys, BCM, or PCM have been replaced. Sporadic starting problems may also be linked to dead batteries, alternator issues, or evap system complications. Furthermore, a common cause of a clicking sound with no start is a dead battery, highlighting the importance of checking the battery and its cables. If the vehicle continues to have starting problems, further investigation into these potential causes is recommended for effective resolution.