What is the reason for not being able to start the car when in P gear?
2 Answers
Not being able to start the car when in P gear is because P gear is the parking gear, which prevents the car from starting. Here is more information about the P gear: 1. Concept: P gear is the most common gear in automatic transmission models, usually located at the frontmost position of the gearshift console, in front of the R gear. Its purpose is to lock the axle when the car is stationary on a slope. 2. Working principle: P gear evolved from the N gear. In addition to placing the transmission in neutral mode, it also has a pawl inside the transmission that locks the gear on the output shaft to form a mechanical lock, thereby securing the drive axle to keep the vehicle stationary or slightly moving. 3. Usage: The P gear should only be used when the vehicle is completely stopped; otherwise, the mechanical parts of the automatic transmission may be damaged. When the vehicle is parked and not in use, the gear is in this position, and the wheels are mechanically locked to prevent rolling.
One night, I parked my car in an open-air parking lot. The next morning after work, I tried to start it to drive home, but even though the gear was in P, turning the key wouldn't fire up the engine. I was frantic and tried several times—the engine whirred but wouldn't start. Later, a mechanic at the repair shop told me that this situation is often due to a weak battery: cold weather accelerates aging, and insufficient charge prevents startup. Check the battery voltage; if it's below 12 volts, recharge or replace it. If the battery is fine, it might be a gear position sensor issue: it tells the computer the gear is in P to allow ignition, but if the switch is damaged or the wiring is loose, it won't send the signal. Sometimes the starter relay also fails—it's not expensive but requires professional diagnosis. He suggested starting with simple self-checks, like measuring the battery voltage, and if that doesn't work, visit a 4S shop to avoid bigger problems from delay. Safety first—if stranded, turn on hazard lights and pull over.
