What Causes an Automatic Transmission Car to Fail to Shift Gears?
2 Answers
Automatic transmission cars may fail to shift gears for the following reasons: 1. Gear lock is engaged: If the gear lock is engaged or stuck, the gear lever will inevitably fail to shift. In this case, try unlocking the gear lock with a key. If it still doesn't work, check the brake. When stepping on the brake, observe whether the brake light turns on. If the brake light does not illuminate, it indicates a faulty brake switch. The car's computer cannot detect whether the brake is engaged, thus preventing gear shifting. The brake switch needs to be replaced promptly. 2. P-lock mechanism is stuck and cannot reset: It needs to be manually reset. 3. Shift solenoid valve is damaged and cannot execute shift commands: A repair shop should be contacted to replace the solenoid valve. 4. Gear shift cable is damaged or broken: The cable needs to be repaired. 5. Control computer malfunction: In this case, contact a 4S shop or repair shop for professional maintenance.
I've been driving automatic transmission cars for over a decade, but last month I encountered a situation where I couldn't shift gears, which scared me into pulling over to check immediately. Upon inspection, I found that the transmission fluid level was too low – insufficient fluid leads to inadequate internal pressure, causing gear lockup. Additionally, the hot weather at the time might have triggered the transmission's protective mode due to overheating. I also tested the brake switch issue because automatic transmission cars generally require pressing the brake pedal to shift gears, and a faulty switch would prevent this function. More commonly, it's caused by shift cable or sensor failures, especially in older models. If you encounter this situation, never force the car to move – try turning off and restarting the engine first. If that doesn't work, call a tow truck to take it to a professional repair shop. During regular maintenance, pay close attention to the shifting system and fluid condition – periodic inspections can prevent problems before they occur.
