* Park/Neutral Safety Switch: This is the most common culprit. This switch prevents the car from starting unless it's in park or neutral. If it's faulty, it might not be sending the correct signal to the ignition system, thus preventing the shifter from moving.
* Shift Cable Adjustment: The cables that connect the shifter to the transmission might be misadjusted, stretched, or broken. This would prevent proper movement of the transmission's shift mechanism.
* Transmission Issues: While less common, problems within the transmission itself, such as low fluid, worn components, or internal failures, can interfere with shifting.
* Broken Shifter: Though less likely, a physically broken or damaged shifter mechanism inside the car could prevent it from moving out of park.
* Low Transmission Fluid: Low fluid can cause various transmission issues, including difficulty shifting.
Troubleshooting Steps (in order of increasing difficulty):
1. Check the brake pedal: Make absolutely sure the brake pedal is firmly depressed. Most automatics require this to shift out of park.
2. Shift lever movement: Try gently rocking the shifter back and forth while applying firm pressure on the brake. Sometimes a little persuasion helps overcome minor sticking.
3. Try the emergency release: Some vehicles have a small button or lever near the shifter that allows you to manually release the shift lock. Consult your owner's manual to see if your 2002 DTS has one. Use this carefully, as you don't want to accidentally move the shifter while the car is running.
4. Check the transmission fluid: Check your owner's manual for the location of the dipstick and the correct fluid level. Low fluid is a serious problem.
5. Inspect the shift linkage: If you're comfortable working under the car, visually inspect the shift linkage for any obvious damage, looseness, or disconnections. This requires some mechanical aptitude and knowledge of your vehicle's specific layout.
If none of the above works: You should take your Cadillac DTS to a qualified mechanic. Diagnosing transmission or electrical problems requires specialized tools and expertise. Attempting repairs without the proper knowledge could worsen the problem.
