What are the reasons why an automatic transmission sometimes doesn't move when shifted?
2 Answers
The reasons why an automatic transmission sometimes doesn't move when shifted are: 1. The gear is not fully engaged; 2. The vehicle's handbrake is not released; 3. The gear synchronizer in the transmission is stuck; 4. Reverse gear oil circuit leakage; 5. Reverse gear and high gear clutch failure or reverse gear brake slippage. The steps to start an automatic transmission car are: 1. Get in the car, insert the key, turn it to the second ignition position (power mode), and wait for the system self-check to complete; 2. Shift the gear lever from P to N; 3. Release the brake and start the car's engine; 4. Press the brake pedal with your foot, shift the gear lever from N to D, release the brake, and press the accelerator to start.
I've seen plenty of cases where automatic transmissions won't move when shifted. Common causes include insufficient or dirty transmission fluid, leading to inadequate hydraulic pressure and sluggish response from the shifting mechanism. Another possibility is sensor failure, such as issues with speed or position sensors, which can cause the control module to lock the transmission if it doesn't receive the correct signals. Occasionally, the electronic control unit might malfunction and send wrong commands preventing the car from moving. I recommend starting with the basics: check the transmission fluid yourself. Find the dipstick—if the fluid is clear and at the full mark, it's good; if degraded, replace it immediately. If your car has an OBD port, plug in a diagnostic tool to read any trouble codes to avoid unnecessary tinkering. Regular monthly maintenance with high-quality fluid can reduce such issues—don’t wait until problems become severe, as repairs can get expensive.
