Hyundai Repair: Hyundai Excel Sprint 1992 Model, hyundai excel sprint, lever release button

Question
With my Father's 1992 Excel Sprint, after he starts the engine, the automatic gear change lever release button remains locked for a few minutes.   Applying the foot brake doesn't allow the gear change lever release button to be pressed for those few minutes.   Eventually, after waiting those few minutes, applying the foot brake does allow the gear change release button to be pressed in, thereby allowing the gear change lever to be selected into gear.

Answer
Hi, Mark.  Your father's shift interlock is controlled by a key lock and control module.  This module decides whether to release the shifter based on input from the ignition switch, park position switch, and the brake pedal switch.  If the proper conditions are met, it will energize a solenoid, relesaing the shifter.  When the gearshift is in park and the ignition is on, you should hear a click from the shifter when the brake pedal is depressed.  The click is the solenoid releasing the shifter.  

Start by checking the brake lamps when the problem is occurring.  If they do not work, suspect the brake lamp switch is defective.

Next, remove the console and check the condition of the detent pin on the shifter.  It should be straight and should move smoothly in the slot in the shift lever.  I don't particularly believe this will be the problem since the issue goes away after warming up, but this is nonetheless a simple check to make.

If these items are all okay, I'm going to suggest that you register for a free account at www.hmaservice.com.  Once there, look at the key lock and control schematic in the ETM (Electrical Troubleshooting Manual) section.  I'm hoping this will be similar to the system on your father's car in Australia.  

You'll want to test for appropriate input from the brake switch, the park position switch, and power.  If okay, you'll want to test whether the module energizes the solenoid.  I don't have any recommendations at this point, since I've seen issues with the module, the park position switch, and the solenoid.  So you'll want to verify with testing which component is defective.