What causes the car to move backward when starting in D gear?
3 Answers
Hanging D gear is: When the car is in D gear, the speed is very slow, which may cause the car to move backward. D gear is the most common gear in automatic transmission models, usually located in the middle and rear of the operation panel. Additional information: 1. Generally, automatic transmission cars have six gears, from top to bottom: P gear, R gear, N gear, D gear, S gear, and L gear. P gear is the parking gear, R gear is the reverse gear, N gear is the neutral gear, D gear is the drive gear, L gear is the low gear, S gear is used for sport mode, and OD gear is the overdrive gear. 2. Starting hill start assist: On a slope, the car might roll backward, so hill start assist should be activated. Put the car in D gear, press the brake, release the handbrake, and press the brake firmly. Then, when released, the car will hold for 2 seconds before power is applied.
Last time I encountered a similar situation while driving, the car rolled backward when in D gear, possibly due to a malfunction in the transmission's gear position sensor. This component is responsible for informing the computer about the current gear. If it misreads the signal, it might mistakenly think the car is in reverse gear, resulting in the car moving backward when starting in D gear. Internal clutch adhesion in the transmission could also cause this phenomenon—the clutch, which should engage for forward motion, might get stuck and act in reverse. Other causes include loose shift linkage or hydraulic system leaks, where fluid loss prevents proper gear shifting. If you encounter this issue, pull over immediately to check—don't force the car to drive, as it could damage the drivetrain. Remember to perform regular transmission maintenance, such as changing the fluid and filtering out contaminants, to prevent many potential failures. Safety comes first—if this issue isn't resolved, it could lead to an accident the next time you start the car.
From my experience, this is quite common and often happens because the gear lever isn't fully engaged when shifting. If an automatic transmission car moves backward in D gear, it might be due to a loose connection between the gear and the transmission, causing incorrect signal transmission; or there could be a bug in the transmission control unit sending wrong commands that make it move in reverse. Another possible reason is the vehicle being parked on a slope, where the transmission responds slowly, causing a slight roll. I recommend first restarting the vehicle and trying to shift gears again to see if it behaves normally. If it still moves backward, you should take it to a professional shop to check the electrical circuits and mechanical components. When driving, pay attention to the feel of the gear lever and make sure you hear a click before releasing the brake. Addressing issues early with minor repairs is sufficient, but if left unattended, replacing the entire transmission can be costly.
