What Causes an Automatic Car to Suddenly Stop While Driving?

[McTanner]

While driving, you may suddenly feel a deterioration in acceleration performance, as if the transmission has shifted into neutral, causing the car to gradually come to a stop; or the car may not move when starting in gear. When diagnosing the issue, the first step is to determine the location of the fault. You can start by checking the condition of the two rear wheels. If both rear wheels are dislodged, it could be due to a broken axle housing or the wheel bearing lock nut coming loose. If everything appears normal, the issue should be assessed based on the behavior of the driveshaft when starting in gear. Below is some relevant information about the transmission: 1. Introduction: A device that changes the speed ratio and direction of motion. It is used to alter the torque, speed, and direction of motion transmitted from the driving shaft to the driven shaft under different working conditions. A gear-driven transmission typically consists of a housing and several gear pairs. 2. Function: While driving, to adapt to varying conditions, the car's driving force and speed need to change within a certain range. However, the existing engine's torque and speed variation range cannot meet this requirement, hence the need for a transmission.

[LeLandon]

I encountered this situation a while ago during a long-distance drive. I was driving an automatic SUV, and suddenly at 60 km/h, it felt like the power was completely drained and the car wouldn't move. Later, at the repair shop, they found that the transmission solenoid valve was stuck, causing abnormal oil pressure. Besides this common issue, it could also be transmission slippage, such as burnt clutch plates; or the shift computer suddenly crashing, especially in older cars with aging wiring. Additionally, a sudden fuel pump failure or a clogged filter can cause the engine to lose fuel. Once, I saw a neighbor's car go into high-temperature protection mode due to poor cooling, directly locking the transmission—it was really scary. I recommend turning on the hazard lights immediately, pulling over to check, and avoiding driving further to prevent damage to the driveshaft.

[SanLyla]

As a veteran driver with twenty years of experience, I can tell you that automatic transmission failures are usually caused by issues in the power transmission system. In recent repair cases, 30% were due to deteriorated and clumped transmission fluid, which blocks the valve body and stops the car. It could also be a failed one-way clutch inside the torque converter—if it slips, power can't be transmitted. Another common issue is faulty sensors, especially the vehicle speed sensor; if it fails, the computer gets confused. One car had its undercarriage scraped by a rock, damaging the transmission wiring harness and causing a short circuit, leaving it stranded. Remember, in such situations, first shift to neutral and restart to see if power can be restored.

[FinleyAnn]

Last time I drove my bestie's new energy vehicle, I experienced this nerve-wracking situation—suddenly losing power while stuck on the ring road was terrifying. The mechanic said it was the battery management system triggering a protection mechanism. Actually, fuel vehicles are similar; electrical faults can lock the gear in neutral. The inspection sequence is crucial: first, check if there are any warning lights on the dashboard—a red indicator means the transmission is overheating; then listen to see if the engine is still running—if it stalls, it's a fuel supply issue; finally, inspect the shift lever linkage mechanism. Last time, a customer spilled milk tea inside, causing it to jam. Keeping an OBD diagnostic cable on hand is very useful—plugging it in can read the fault codes.

[Jacob]

Over the years of ride-hailing, I've witnessed numerous sudden breakdown cases, especially frequent during summer heatwaves. Focus on these three areas: Insufficient transmission fluid can trigger protection mode—some vehicles have dipsticks on the left side of the engine bay; fractured turbine blades in the torque converter can cause abrupt loss of torque transfer; and differential gear teeth breakage is another mechanical failure. Never overlook minor issues—I once delayed a transmission fluid change, resulting in sludge clogging the filter and stranding me on an elevated highway. Now I inspect chassis bushings monthly, as worn driveshaft universal joints can also suddenly disengage.