Here are some of the most common culprits:
* Low or contaminated transmission fluid: This is the first thing to check. Low fluid can cause all sorts of shifting problems, and dirty fluid can prevent proper clutch engagement.
* Faulty shift linkage: A problem with the linkage connecting the shifter to the transmission could prevent it from selecting higher gears.
* Internal transmission problems: This is the most likely scenario. Worn clutches, bands, or other internal components can prevent the transmission from shifting correctly. This could include a broken shift valve or solenoid.
* Torque Converter Issues: A problem with the torque converter could also prevent proper shifting.
While a computer problem *could* theoretically cause this, it's far less common. A computer failure would usually manifest in a more erratic pattern of shifting issues (sometimes shifting, sometimes not, maybe skipping gears) rather than a complete inability to shift out of first. A faulty sensor is also possible but still more likely to cause a different symptom set.
Before concluding the transmission is bad, start with the basics:
1. Check the transmission fluid level and condition. Is it low? Is it dark, burnt, or smelling bad? If so, this needs addressing urgently.
2. Check the transmission fluid lines for leaks.
If the fluid level and condition are good, then a professional mechanic is needed to diagnose the internal transmission problem. They'll have the tools and expertise to determine the precise cause. Simply saying "it's the transmission" is unhelpful without further diagnosis.
