So is the battery in good condition? Does it have 12.4 volts at the terminals? If not the either charge it or change it. Then check to see if the brake lights are working as if not then it may be the brake light switch is faulty which in turn will cause the P lock solenoid not to operate Other than that it may be the gear lever solenoid has failed. If you check in your drivers manual there is a procedure to override the gear lever when stuck.