When can the P gear of an automatic transmission be used?

[AubreyFitz]

Automatic transmission's P gear can be used when parking. The P gear locks the transmission. On very steep slopes, remember to firmly engage the handbrake, otherwise it may cause damage to the transmission locking mechanism. Whether using a gear lever or a rotary knob to switch to P gear, after pushing to P gear triggers the electrical signal, the control unit will engage the pawl into the ratchet wheel. During parking, the pawl and ratchet wheel are only engaged without contact, remaining in a ready state, and the pawl won't be damaged even with prolonged use. If the ratchet wheel actively outputs torque, the consequences could be quite severe. If the vehicle is rear-ended at high speed while parked in P gear, the best possible outcome would be the ratchet wheel pushing against and bouncing off the pawl, or the pawl deforming while the ratchet wheel remains undamaged.