What Causes Abnormal Noise in Car Audio?

What does it mean when the ABS light on the dashboard is on?

When the ABS light is displayed on the car, it indicates a malfunction in the vehicle's Anti-lock Braking System. If the wheels lock up during emergency braking, the vehicle may lose control and skid, making it difficult for the driver to slow down or adjust the vehicle's trajectory, which poses significant safety risks. There are various states in which the ABS light may illuminate, with different causes and solutions for each state, as detailed below: State 1: ABS warning light remains constantly on (most common). Cause 1: The ABS wheel speed sensor's sensing part is covered by dirt, mud, or other contaminants, affecting the sensor's ability to detect the corresponding speed signal. This prevents the ABS computer from determining the vehicle speed and the wheel slip rate, thus failing to issue appropriate commands to regulate braking. Solution: Clean the dirt from the wheel speed sensor and adjust the gap between the sensor and the signal ring to restore normal function. Cause 2: Poor signal due to loose connections in the system wiring or poor contact in the ABS relay, leading to system failure. Solution: Check the wiring connections and reconnect any loose parts. State 2: ABS warning light intermittently illuminates but turns off during acceleration. Cause: When multiple vehicle electrical devices are in use, the battery voltage drops below 10.5V. As the engine speed increases and voltage rises, the ABS light turns off. This may also occur if the ABS system's power supply voltage is too low due to poor terminal contact or grounding. Solution: Check the battery's specific gravity; inspect the charging system; examine the power supply (e.g., voltage relay or poor power contact). State 3: ABS warning light remains on after engine start and only turns off when the engine is turned off (IGFF). Cause: Poor grounding contact in the ABS hydraulic valve body; poor contact in the ABS hydraulic valve body wiring connector; ABS computer malfunction. Solution: Loosen the grounding screw on the hydraulic valve body, then retighten it, cleaning the contact surface if necessary; check if the connector gap has widened; replace the ABS or ABS/ASR computer. State 4: ABS warning light illuminates during high-speed driving. Cause: During high-speed driving, the ABS computer detects a significant discrepancy between the rear and front wheel speed signals; incorrect tire or wheel rim specifications. Solution: Refer to the vehicle's tire and wheel rim specifications, as indicated on the sticker near the fuel tank cap. State 5: ABS warning light intermittently illuminates. Cause: Improper adjustment of the brake light switch; poor internal contact in the brake light. Solution: Start the engine, press the brake pedal, use a finger to push the brake switch linkage fully downward, then release the brake pedal to complete the self-setting position; replace the brake light switch if necessary.

19

5

Share

Is it better to use 92 or 95 octane gasoline for the VV7?

The Great Wall VV7 can use 92 octane gasoline. The definition of gasoline grades and an introduction to their anti-knock properties are as follows: Definition of gasoline grades: 92 octane gasoline contains 92% isooctane, with the remainder being n-heptane. Similarly, 95 octane gasoline contains 95% isooctane. There is no difference in quality between these two types of gasoline; they are simply suitable for engines with different compression ratios. Anti-knock properties of gasoline grades: Isooctane is related to anti-knock properties, while n-heptane affects the combustion speed. 92 octane gasoline has relatively weaker anti-knock properties, whereas 95 octane gasoline has higher anti-knock properties and a slower combustion speed. Differences between 95 and 92 octane gasoline: The main difference lies in the octane rating, with no other fundamental differences. 95 octane gasoline consists of 5% n-heptane and 95% isooctane, while 92 octane gasoline consists of 8% n-heptane and 92% isooctane. 95 octane gasoline has a higher octane rating than 92 octane gasoline. In terms of stability, 95 octane gasoline burns more easily and delivers greater power output compared to 92 octane gasoline.

14

5

Share

Can a car's license plate be changed?

In principle, it is not allowed to change the license plate. If there are special circumstances requiring a license plate change, you must apply for re-registration at the vehicle management office. Below is the procedure for handling the replacement of a license plate: Required documents: In addition to the vehicle's registration certificate and your ID card, you must bring the motor vehicle registration certificate if it has been processed. For company vehicles, the organization code certificate is also required. Vehicle Management Office: The owner first needs to fill out a license replacement application form at the vehicle management branch. For company vehicles, the form must be stamped with the company's official seal before submission. The vehicle management office will then provide a police receipt and a temporary license plate. The temporary license plate should be placed in a visible position on the vehicle's front windshield for inspection by traffic police. Using a temporary license plate does not affect the annual inspection. If only one license plate is lost, the old plate must be surrendered when applying for a replacement. Waiting: After 30 working days, you can collect the new license plate from the vehicle management office. The new license plate will have the same number as your original one, and your vehicle registration certificate can still be used.

8

0

Share

How to Read Brake Disc Size Data?

There is no need to look up brake disc sizes. If you want to replace your brake discs, simply measure the diameter of the discs after removing them. Below is relevant information about brake discs: Classification of Brake Discs: Brake discs come in many types, including carbon ceramic brake discs, slotted brake discs, slotted and drilled brake discs, double-layer cooling brake discs, and solid brake discs. Things to note when replacing brake discs: The sizes of front and rear brake discs differ, with front brake discs generally being larger than rear ones. When replacing brake discs, it is advisable to choose original equipment manufacturer (OEM) parts or those produced by reputable brands.

14

1

Share

What are the differences between Driving License Subject 1 and Subject 4?

The main differences between Subject 1 and Subject 4 include: the number of test questions, question types, proportion of exam content, and exam focus. The basis comes from the "Regulations on the Application and Use of Motor Vehicle Driving Licenses". Number of test questions: The most obvious difference between Subject 1 and Subject 4 is the number of test questions. Subject 1 has 100 questions, while Subject 4 only has 50 questions. In Subject 1, the test will automatically submit if more than 10 questions are answered incorrectly, while in Subject 4, the test will automatically submit if more than 6 questions are answered incorrectly. Question types: Subject 1 consists of 100 questions, each worth 1 point, with a total test time of 45 minutes. The question types are true/false and single-choice questions, with a full score of 100. Subject 4 consists of 50 questions, each worth 2 points, with a test time of 45 minutes. The questions are mainly in the form of case studies, pictures, animations, etc., and the question types include true/false, single-choice, and multiple-choice questions, with a full score of 100. Exam content focus: Subject 1 mainly assesses basic knowledge of road driving, while Subject 4 focuses on safe and civilized driving knowledge. It can be understood this way: Subject 1 tests how to drive, while Subject 4 tests how to drive safely. Although the difference is just two words (safety), the focus is completely different. Proportion of exam content: Subject 1 exam content composition: Driving license and motor vehicle management regulations account for 20%; Road traffic conditions and regulations account for 25%; Road traffic safety violations and penalties account for 25%; Road traffic accident handling regulations account for 10%; Basic knowledge of motor vehicles accounts for 10%; Local regulations account for 10%. Subject 4 exam content composition: Safe driving knowledge accounts for 20%; Civilized driving knowledge accounts for 18%; Comprehensive application of road traffic signals in traffic scenarios accounts for 8%; Safe driving knowledge under adverse weather and complex road conditions accounts for 16%; Emergency avoidance knowledge accounts for 12%; Typical accident case analysis accounts for 6%; Traffic accident rescue and common hazardous chemical disposal knowledge accounts for 10%; Local test questions account for 10%. There is no limit to the number of attempts for driving test Subject 1 and Subject 4. If the test is failed, it can be rescheduled. Each scheduled test has two attempts. If both attempts are failed, the test can only be retaken until it is passed. Both Subject 1 and Subject 4 are theoretical tests and are part of the motor vehicle driving license assessment. There are a total of 3 subjects in the driving test: Subject 1, Subject 2, and Subject 3. Subject 1 refers to the road traffic safety laws, regulations, and related knowledge test; Subject 2 refers to the field driving skills test; Subject 3 is divided into two parts: road driving skills and safe and civilized driving knowledge test. The safe and civilized driving knowledge test is conducted after Subject 3, so it is commonly referred to as Subject 4. In the official terminology (i.e., the Ministry of Public Security Order No. 123), there is no such term as Subject 4.

1

2

Share

How Often Should a Vehicle License Be Inspected?

Here is the relevant information about how often a vehicle license should be inspected: Operational Passenger Vehicles: Operational passenger vehicles must be inspected once a year within the first 5 years; after 5 years, they must be inspected every 6 months. Medium and Large Vehicles: Trucks and large or medium non-operational passenger vehicles must be inspected once a year within the first 10 years; after 10 years, they must be inspected every 6 months. Small Vehicles: Small and micro non-operational passenger vehicles must be inspected once every 2 years within the first 6 years; after 6 years, they must be inspected once a year; after 15 years, they must be inspected every 6 months.

12

2

Share

What Causes Abnormal Noise in Car Audio?

What does it mean when the ABS light on the dashboard is on?

Is it better to use 92 or 95 octane gasoline for the VV7?

Can a car's license plate be changed?

How to Read Brake Disc Size Data?

What are the differences between Driving License Subject 1 and Subject 4?

How Often Should a Vehicle License Be Inspected?

What Are the Reasons for Car Air Conditioning Not Cooling?

What to Do When There Are Water Droplets Inside the Headlights?

What is Brake Fluid?

At What Age Can You Get a B2 Driver's License?