What Causes an Automatic Transmission Car to Stall While Reversing?
4 Answers
There are several reasons why an automatic transmission vehicle may stall while reversing, including electrical circuit malfunctions, excessive carbon buildup in the fuel injectors or spark plugs, or other electrical issues. Here are the relevant details: 1. Specific causes: Stalling during operation may occur due to low-voltage power interruption, excessive carbon deposits on spark plugs leading to unstable ignition and occasional stalling, or severe engine operation conditions caused by excessive carbon buildup in components like the throttle body and fuel injectors, making the vehicle prone to stalling at low speeds. 2. Electrical circuit malfunctions: Electrical faults, such as low-voltage power interruption during driving, can cause stalling. In such cases, it is advisable to primarily inspect the ignition and starter switches, as well as the fuse box. Stalling caused by short circuits in low-voltage circuits tends to occur intermittently; therefore, checking the low-voltage circuits for component failures is essential.
My old automatic car suddenly stalled while reversing last time, which really scared me. Later, the inspection revealed that the transmission fluid hadn't been changed for too long and had turned black. Such dirty fluid can affect the hydraulic system's operation, and the increased resistance during reversing can easily cause the engine to stall. There was also an issue with carbon buildup in the throttle body—my car had never been cleaned in over 80,000 kilometers, and the carbon deposits clogged the intake like a morning traffic jam. The most surprising discovery was the cracked engine mount bushings, which caused the engine to shake and pull on the wiring harness during reversing. It's recommended to change the transmission fluid regularly, clean the throttle body every 20,000 kilometers, and replace aging rubber parts promptly to avoid problems like mine.
When I first got my driver's license and experienced stalling while reversing, I thought it was an operation issue. Later, my car-savvy friend told me that stalling in an automatic transmission is mostly due to intake system problems. For example, an air filter clogged like a blanket can suffocate the engine; or a stuck exhaust valve causing abnormal crankcase pressure; an oxygen sensor failure can also lead to an imbalanced air-fuel mixture. I remember that time when I opened the air filter box and found a plastic bag stuck inside. Now, my experience is: after stalling while reversing, first check if the idle is stable, inspect the air filter box for any foreign objects, and pay special attention to the lifespan of sensors in older cars. These components are prone to fail under the load changes during reversing when they have issues.
After 12 years of car repair experience, there are three main culprits for common automatic transmission stalling in reverse: aging fuel pump causing insufficient fuel supply, especially noticeable when reversing on slopes; cracked ignition coils leaking electricity, particularly prone to stalling when reversing into parking spaces on rainy days; and oxidized battery terminals leading to poor conductivity. Last week, a Tiguan stalled while reversing, and testing revealed the starting voltage had dropped to 9V. Remember, a faulty coolant temperature sensor can also mislead the computer, causing unstable idle speed control. The simplest first step is to check the battery voltage, which should maintain around 14V when the engine is running.
