What is the reason why the Haval smart key can unlock the door but cannot start the car?

[LaVanessa]

Haval smart key can unlock the door but cannot start the car may be due to the key running out of battery or the key being interfered with. Introduction to Haval: Haval is a sub-brand of Great Wall Motors, established on March 29, 2013. The Haval brand, mainly focusing on SUV models, operates in parallel with the Great Wall brand, using an independent logo and an independent system for product development, production, and services, mainly engaged in SUV production and sales. The brand includes three series: H series, M series, and F series. Smart key functions: When approaching the car. When the driver brings the key in their pocket close to the car, the key and the car begin to exchange preset instructions via radio. The car's locking system, security system, and engine control system are all activated; When opening the door. As soon as the driver touches the door handle, the sensor detects this pressure, and the servo motor unlocks the door. Then the seat, steering wheel, and exterior rearview mirror automatically adjust to the position suitable for the owner; Before starting. When the driver steps on the brake pedal, the steering wheel lock is immediately released. At the same time, the start button is also released, and finally, the main brake is automatically released; When getting off the car. When getting off, the driver must press the lock button. If the flashing light turns on, it indicates that the door is securely locked. At the same time as the car is locked, the key and the car will agree on a new instruction information.

[Jodi]

I've encountered this issue too. Opening the door of my Haval was easy, but pressing the start button just wouldn't work, which was really frustrating. A common problem is weak key fob battery - it might still have enough juice for door operation which requires less power, but starting the engine needs stronger signal transmission that fails when battery is low. Another possibility is signal interference nearby, like other electronic devices in parking lots disrupting communication between key and vehicle. Sometimes the anti-theft system glitches and misjudges, thinking the key doesn't match or it's an illegal start. My suggestion is to first try replacing the battery - just buy a coin-type one from the market, it's easy to DIY replace. If that doesn't work, move to a different location away from potential interference sources, or try using the spare key to start. The last resort is visiting the 4S shop for diagnostics to check for relay or system failures, avoiding potential roadside breakdowns. Safety first - don't delay dealing with this.

[AniyahAnn]

Having worked on car repairs for many years, when a Haval smart key can unlock the door but fails to start the engine, the issue is mostly in the communication chain. If the key battery is too low, the weak signal might still unlock the door, but starting requires higher power transmission—insufficient power causes a break. Signal interference is common, with nearby strong magnetic field devices like charging stations or WiFi routers disrupting the key frequency. The anti-theft module may occasionally malfunction, mistakenly locking the system or causing a key ID mismatch. It's recommended to first check the battery and test with a new CR2032 model. If that doesn’t work, try using the spare key to confirm whether it's a key issue or a vehicle system problem. If necessary, connect a diagnostic scanner to check error codes and locate faults in relays, modules, or wiring shorts. Experienced drivers know that timely repairs save major headaches, ensuring peace of mind on the road.

[RosalieLee]

As a car owner, I often encounter this issue: the key can unlock the door but fails to start the car, which feels frustrating. The usual cause is a nearly depleted battery—unlocking requires minimal power, while starting demands more, and insufficient power prevents ignition. Signal interference is another possibility; nearby electronic devices can disrupt the signal. Try replacing the battery first—it’s simple, just buy a new one from the supermarket and install it. If that doesn’t work, place the key near the start button; some cars have a sensor area for resetting. A mechanic once reminded me that a triggered anti-theft system can also cause this—check if the dashboard lights are flashing. Address it promptly to avoid the hassle of being stranded at night.