Light on the Transmission Shifter went out

Press the "S" button on the shifter handle to disengage the sport mode, press it again to re-engage it.

It won't crank because it is in reverse. First remove the linkage at the transmission and put it in park or just see if the transmission shifter will move. If it does, then look to the cable or shifter in the console/column. If the transmission shifter doesn't move, It is an internal transmission problem. Most can be repaired by removing the valve body. Via the transmission oil pan. Some the transmission has to be pulled .

on top of transmission you can see the shifter cable remove it from lever. Try to move lever freely try to move the shifter if it stuck again
could be cable or transmission internal
hope it helps

There is a rubber bushing that sits inside the shift linkage that wears out over time. It will not damage the trans if you drive it that way. It is just a little noisy and sounds bad when moving the shift lever.

Transmission problem....Unless your a mechanic (assuming you arent since you came to fixya haha) thats something you'll have to take to the shop.

Can you disconnect the shifter at the transmission and move the shift arm ? Make sure the parking brake is set first.
You may have to disassemble the steering column to un-jam the key cylinder and shifter.

it can be a few different places. Some cars they are mounted to the shifter assembly(Underneath the center console), some they are mounted on the transmission(externally), and some are internal.

Neutral Park/BackUp Lights Switch - REPLACEMENT & ADJUSTMENT

1. Remove the console trim from the console.
2. Disconnect the electrical connector from the switch.
3. Remove the 2 attaching screws from the switch and remove the switch.

1. To install a new switch:
   1. Place the switch onto the transmission control shifter and loosely install the attaching screws. Position the transmission control shifter assembly in the N notch in the detent plate.
   2. Assemble the switch to the transmission control shifter assembly by inserting the carrier tang into the hole in the shifter lever.
   3. Install the attaching screws and tighten.
   4. Move the transmission control shifter assembly out of N position. This will shear the switch internal plastic pin.
      
   
   
2. To install the original switch:
   1. Place the switch onto the transmission control shifter and loosely install the attaching screws. Position the transmission control shifter assembly in the N notch in the detent plate.
   2. Rotate the switch on the shifter assembly to align the service adjustment hole with the carrier tang hole. Insert a 3 / 32 in. (2.38mm) diameter gauge pin to a depth of 9 / 16 in. (15mm) and tighten attaching screws.
   3. Remove the gauge pin.
   
   
3. Connect the electrical connector to the switch.
4. Install the console trim to the console.

Fig. 1: Neutral start/back-up light switch

Hope this helps (remember to rate and comment this).

Just had the same problem. The problem is that the rubber bushing on the transmission linkage deteriorates and falls off. This causes two problems - shifter is loose and a metallic clunking sound is heard when shifting. It's not the shifter inside the car. It's the linkage underneath the car. You have to buy the bushing (if sold by itself) or the linkage kit. The linkage is on the passenger side of the transmission between transmission and right side exhaust pipe. Ensure engine/exhaust is cold prior to trying to access. Regards.

I have the same problem on my 2005 cts. The shifter fork has two rubber bushings that attach at the transmission that break or give way. I assume they did this for a softer feel and to avoid vibration but it leads to the selector not engaging well when you go the extreme direction of reverse on the shifter as there is too much deflection. I replaced the bushings with washers as spacers and it seems to work as a "McGyver" fix. I do intend to get the parts needed from Cadillac to restore it to factory standards. Hopefully they have the parts. To fix the problem you have to go under the car. To get good access you have to disconnect the exhaust and the driveshaft. I did it without this and just tormented my poor hands but I wasn't willing to do all the other work while in my driveway. You simply take the clip holding the fork shaft onto the transmission selector end off and slide the small shaft out. I also took off the shifter side of the fork to study the thing a bit better. That takes a 13mm and a small allen wrench, 4.5 or 3/16, can't remember. Then replace the bushings or do as I did and stack some washers so as to get rid of the slack between the inside of the fork and the gear selector on the transmission. Assemble and try. If you have as good dexterity and tenacity at your fingertips as I do, you'll curse the day you attempted doing this without taking out all the other stuff. If you don't, take out all the other stuff to make room for your hands. The space is very confined. Good luck.