Is it necessary to go to a 4S shop to clear the fault code?

[OAnthony]

Clearing fault codes does not necessarily require going to a 4S shop. Fault codes: Automotive fault codes are the codes reflected by the vehicle's computer ECU after analyzing a fault. Generally, fault codes are caused by sensor malfunctions or poor sensor performance, but some mechanical faults cannot be read by the ECU. When a car engine malfunctions, the diagnostic computer will display the fault code after detection. Through this code, maintenance personnel can accurately locate the faulty component and proceed with repairs. Solutions: Check for open or short circuits in the wiring connecting the ignition switch, ECU, fault warning light (CHECK), and communication interface. The ECU may malfunction, causing abnormal self-diagnosis output signals. The fault warning light (CHECK) or communication interface may also be damaged.

[ORose]

I'm quite qualified to speak on this issue, as I did thorough research when my car's engine warning light came on last time. Actually, you don't necessarily need to go to a 4S shop to clear trouble codes - many auto repair shops now have professional diagnostic tools, with basically the same operation procedures as 4S shops, but saving half the labor cost. For example, at the chain quick-service shop I frequent, they can read OBD data with their own equipment and only charge 50 yuan for code clearing. Of course, if your car is still under warranty, prioritizing a 4S shop is wise since it involves warranty records. But it's important to note that simply clearing codes is just a temporary fix - the key is having the technician use the diagnostic tool to properly identify the root cause of the issue. Otherwise, the light might turn off only to come back on in a couple days, which would be more troublesome.

[MacEverett]

I've cleared temporary fault codes several times using a Bluetooth OBD scanner myself. Just buy a small square box online for a few dozen yuan, plug it into the OBD port under the steering wheel, and download a professional app on your phone to read fault information. Like last time when my Volkswagen reported P0420 (catalytic efficiency below threshold), it was actually a fuel quality issue. After clearing the code and filling up with two tanks of 95-octane gasoline, the problem never reappeared. Of course, this kind of operation is only suitable for temporary faults that don't affect driving safety. If it's a serious issue like engine shaking or brake system failure, don't try to clear the codes yourself - you must seek professional help. Nowadays, most repair shops outside have professional equipment, especially those specializing in German or American cars - their tools are no worse than those at 4S stores.

[EvaLee]

It depends on the nature of the fault code. Once my old LaCrosse had the ABS warning light on, and after clearing it at a roadside shop, it came back on after two kilometers. It turned out to be aging wiring harness of the wheel speed sensor. For such persistent faults, forcibly clearing the code is meaningless; the root cause must be addressed. Nowadays, many brand-specific repair shops have factory-level diagnostic computers. For example, the Toyota specialist shop here uses Techstream to fully read data streams. However, it's worth reminding everyone that for fault codes related to airbags, brakes, or steering systems, it's advisable to go to a 4S dealership for handling. Their systems can access the manufacturer's latest database.

[DeMargaret]

Just helped my neighbor with this issue last week. His car showed a P0171 code for lean fuel mixture, which could actually be fixed by simply replacing the air filter. But the dealership quoted over 3,000 yuan to replace the entire intake pipe. Later, I took him to a trusted repair shop where they used a Launch X431 scanner to clear the code and clean the throttle body, solving the problem for just 300 yuan. Nowadays, many third-party repair shops have diagnostic equipment covering mainstream models, some even newer than what dealerships use. However, it's important to choose certified shops—I once saw someone mess up by using a cheap code reader bought on Taobao, accidentally clearing the transmission adaptation values.