92 SC300 Stuck in park - Shift Lock Override NOT WORKING!
 

Hello all,

Recently, I decided to replace the old decrepit stock radio in my 92 SC300. I made all the necessary connections and all that did everything correctly and the radio works fine. (hurrah) Immediately after changing out the radio I went to auto zone to pick up some hardware that I needed to replace for all of the trim panels. And then she got stuck in park. I thought, "no big deal this happens occasionally, I'll just hit the shift lock override." nothing. She wouldn't budge. I googled it and I found that this happens much of the time whenever a fuse is blown for one reason or another. At this point I realized that I had committed the ultimate sin in working with radios.. I forgot to disconnect the battery. After feeling like a total turd for about 45 seconds I checked the fuses and to my delight, it seems the horn fuse was blown and the horn wouldn't work. (I checked all fuses) Changed the fuse, tried to move out of park... still stuck in park. :banghead: Eventually, after messing with it for several hours, I gave up and called a tow. They towed the car using blocks and dropped it off at the house. There it sat for several weeks as I had to go out of town on business. I came back today and figured since the battery had died, that I would check to see if I could jump it and maybe the ECU was not allowing me to shift for some reason. I jumped it, and still nothing. I did more research today and I found that often times, it is the brake switch. I checked to see if the brakes work, they do. Other things are saying it could be the ECU, or the Neutral safety switch or possibly the solenoid itself in the center console. Does anyone have any way of knowing for sure what the problem is? I'd really like to troubleshoot this properly before I start shot-gunning parts at it. There is also no audible click when depressing the brakes.

TL:DR:

Changed Radio, forgot to unplug battery. (because I'm a dummy) Stuck in park. Blown horn fuse. Replace fuse, still stuck in park but horn works.
Shift Lock Override does nothing.
Brake lights work fine.
No audible click in cabin when depressing bake pedal
No soda or gunk residue in center console
Checked all fuses, will check again.
Images for Clarity.

Attachment 400438Attachment 400439

Isn't the shift lock override purely mechanical? It's been a while since I've dug down there, but I don't recall it having an electrical component.

If so, you should be able to peer down at the metal teeth of the shifter mechanism and see if the shift lock isn't disengaging properly. Maybe something got jammed down there or pushed out of place when you were doing stereo work.

That's what I thought but apparently it isn't. I wish a had a general systems book on it so I could read how it actually operates and I might be able to diagnose it better. From what I can tell, the override linkage is engaged properly and works as advertised, but I'll take another look at it regardless.

if you have a 92-97 , this is how your automatic shifter looks like

Attachment 416687

when you press the brake pedal with ignition switch on , the motor on the left which I encircled is activated thus pulling the lock lever on the right which prevents the shifter from being moved from the park position

Attachment 416688

If that motor is broken , the override (black square button on top) which you manually push moves to the left a lever that pulls the lock manually. Your problem on the manual override might be broken plastics / linkages. There should be no reason to unlock it manually if everything in there is in good shape on those plastic linkages.

Attachment 416689

I went back and looked at the linkages.. nothing seems to be broken and the arm retracts as normal. Are you certain there is no electronic action going on here with the mechanical linkage?

both motor and manual override pulls the same pin that prevents the shifter from moving ..

when you press the manual overide, do you see the pin with that white round loop being pulled ? The one I encircled in yellow . That pin with a white loop is both connected to the motor and the manual override through the linkages. They both pull that pin out towards the left. If motor is bad, manual overrides makes you pull it manually . IF YES , then the shifter is definitely UNLOCKED and not being able to move the shifter is definitely a different problem and not because it is still locked by that lock pin.

Attachment 416660

check if the black mechanical switch on the right of the shifter hasn't fallen apart internally that is preventing the shifter to move. The shifter has a notch that moves inside that black switch on the right to do all the mechanicall switching and if there is something mechanical that is dislodged in there , it can prevent the shifter to be moved. If there is nothing wrong on that black switch .. then there are two linkages at the bottom of the car near the transmission ... one on both end of the long bar but they are just bolts ... then the transmission itself

Nothing else ....

So this is what I was able to come up with... I made a video to explain. Please correct any incorrect assumptions regarding what I found.

So , your manual override works ... the problem I see as I mentioned previously , it looks like it is the black mechanical switch on the right of the shifter . Looks like something had been misaligned there so when you press the shifter button , looks like it won't disengage from inside that black mechanical switch.

there are two screws on that black mechanical switch... take them out and see if you can move the shifter . Your next problem once that is out is you cannot take out the key because that mechanical switch is what allows you to turn the key to the lock position and be able to take out the key .. let's deal with that later. You can actually disconnect one terminal of battery and you should be able to remove key.

but first resolve your first problem .. find out if that switch is what is preventing the shifter to move by removing those two screws .

So the epic saga continues...


We cleaned up the switch, re-installed in correctly and lubed up correctly.. went to move the shifter around and it works!! :D

Bad news is when I started it up to test it, it started pouring white smoke and it smelled like gas. :cry:

I'm assuming this is due to a faulty ECU. Where should I go to fix this issue?

Thanks for all your help, you are helping me out big time!

Drive it around .. its winter time. You haven't use the car in a while. It maybe condensation gathered in your exhausts . Check if after a couple of hours driving if it still spewing white smoke and see if the car overheats !

Before you know it , there is nothing wrong with your car .

You were right. (I'm noticing a pattern)

It's not blowing smoke anymore and seems to be smoothing out. But it's still punishing me for sitting for that long because now the turn signals aren't working. lol.

Thanks again!