What are the reasons for a car not moving when stepping on the accelerator in D gear?

[OKate]

The reasons for a car not moving when stepping on the accelerator in D gear are as follows: 1. Broken half-shaft sleeve or loosened wheel hub bearing lock nut: When shifting into gear and starting, the car does not move. The first step in diagnosis is to determine the location of the fault. Check the condition of the two rear wheels first. If both rear wheels are thrown out, it may be due to a broken half-shaft sleeve or a loosened wheel hub bearing lock nut. Solution: Repair the half-shaft sleeve or wheel hub bearing lock nut. 2. Rear axle failure: If the drive shaft rotates but the car does not move, the fault lies in the rear axle. Solution: Jack up the rear axle and rotate one rear wheel. If the drive shaft does not rotate and the other rear wheel rotates in reverse, it indicates that all the rivets of the driven bevel gear are sheared. If the other rear wheel also does not rotate, disassemble and inspect whether the half-shaft is broken. 3. Transmission failure: If the drive shaft does not rotate when the transmission is in a certain gear after the car starts, the fault lies in the transmission. Solution: Remove the transmission cover and check whether the transmission fork is broken or the guide block fixing screws are loose. 4. Clutch failure: If the drive shaft does not rotate in any gear of the transmission, the fault lies in the clutch. Solution: Check whether the clutch is severely slipping, whether all the spline teeth of the clutch driven disc hub and the steel plate rivets are sheared, or whether the steel plate is broken.

[JeffreyDella]

The car won't move when pressing the accelerator in D gear, which I've encountered several times and it's quite frustrating. The most common issue is transmission problems, such as insufficient or deteriorated transmission fluid, preventing the hydraulic system from properly transferring power, resulting in the engine roaring but the wheels not moving. Another possibility is a faulty clutch or torque converter, which are prone to issues in automatic transmissions, especially after frequent traffic jams. Additionally, loose or broken driveshaft connections can lock the wheels. The electronic system is also to blame; if the gear position sensor fails, the car might mistakenly think it's still in neutral. A reminder: always check if the handbrake is fully released, a common mistake for beginners. Regular transmission maintenance can reduce such failures, especially for older cars. Last time, I solved it by timely fluid replacement, avoiding the risk of breaking down midway.

[MacColeman]

For daily driving, if the car doesn't move when in D gear, start troubleshooting from simple steps. First, confirm the handbrake is fully released—often this small oversight causes the vehicle to stall. Second, insufficient or deteriorated transmission fluid can affect power transfer; check the fluid level under the hood. Third, damaged drivetrain components like drive shafts or differentials can immobilize the car as if anchored. Electronic factors shouldn't be ignored either, such as gear module failure or engine control system errors cutting off power. For new cars, check for available ECU software updates. For prevention, develop a habit of checking fluids before starting, and have a technician inspect the drivetrain regularly—don't wait for issues to arise, as repairs then become costly, time-consuming, and dangerous.

[ClaytonDella]

When a car doesn't move in D gear despite pressing the accelerator, it's often caused by transmission-related issues. Possible reasons include hydraulic failure due to fluid leakage, or the torque converter's lock-up mechanism being stuck and unable to transfer engine power. A broken driveshaft or loose connectors can also stop the wheels. On the electronic control side, the gear position sensor might give false readings, causing the ECU to misinterpret the gear and cut off power output. Another common issue: if the engine's intake system is clogged or spark plugs are faulty, the engine won't generate power, and the car won't move forward. It's recommended to first check the fluid levels and handbrake, then seek professional diagnosis to prevent minor issues from escalating.