* Brake Light Switch: This is the most common cause. The switch tells the transmission it's safe to engage. If the switch is faulty, broken, or misadjusted, it won't send the signal, preventing the car from shifting. This is an easy and inexpensive part to replace.
* Neutral Safety Switch: Similar to the brake light switch, this switch prevents the car from starting unless it's in Park or Neutral. A malfunctioning neutral safety switch can also interfere with shifting into gear, even if the brake is pressed.
* Transmission Range Sensor (PRNDL): This sensor informs the car's computer about the selected gear position (Park, Reverse, Neutral, Drive, etc.). A faulty sensor can lead to incorrect shifting behavior or inability to shift at all.
* Low Transmission Fluid: Low fluid levels can cause various transmission problems, including the inability to engage gears. Check your transmission fluid level (using the dipstick while the engine is running) and top it off if necessary. *However, if the level is low, there's likely a leak, which should be addressed before driving.*
* Transmission Problems: Less likely, but possible, is a more serious internal transmission issue. This could include problems with the valve body, solenoids, or other internal components. This usually involves more expensive repairs or even a transmission replacement.
* Shift Cable: While less common in automatics, a problem with the shift cable linkage could prevent the transmission from receiving the correct signal.
Troubleshooting Steps:
1. Check the brake lights: Do your brake lights work when you press the brake pedal? If not, the brake light switch is a prime suspect.
2. Check the transmission fluid level: Ensure the fluid level is correct. If low, look for leaks.
3. Try starting the car in neutral: See if it starts. If it doesn't start in Neutral, but it does when in Park, you might have a neutral safety switch problem.
4. Inspect the shifter linkage: Examine the linkage around the shifter for any obvious damage, looseness, or binding.
5. Have it professionally diagnosed: If the above steps don't solve the problem, take your Tracer to a qualified mechanic or transmission specialist for a proper diagnosis. They have the tools and expertise to determine the exact cause.
Ignoring this issue can lead to further damage and more expensive repairs. Addressing the problem promptly is recommended.
