What is the working principle of an automotive transmission?

What are the symptoms of a faulty expansion valve?

Automotive expansion valve failure symptoms include: 1. Low-pressure pipe not feeling cold to the touch; 2. Frost formation on the dryer and condenser; 3. No hissing sound heard at the expansion valve or condenser. More information about the expansion valve is as follows: 1. The principle of the expansion valve controller is: The system flow is controlled via an electromagnetic coil as the medium. Before the electromagnetic coil is energized, the valve needle is in an open state. After the electromagnetic coil is energized, the opening degree of the valve needle is controlled by the voltage on the electromagnetic coil to regulate the flow of the expansion valve. 2. The method for checking the condition of the expansion valve is: Connect the expansion valve to the high and low-pressure ends of the manifold pressure gauge, with the middle hose connected to the charging valve and injecting refrigerant; Place the capillary tube of the expansion valve into a water tank, observing the water temperature in the tank and the pressure on the high-pressure gauge; Operate the high-pressure manual valve to make the high-pressure gauge pointer reach 490kpa, allowing the refrigerant to discharge from the expansion valve in a gaseous state; If the intersection point of the water temperature and high-pressure gauge pressure values falls between the water temperature and high-pressure curves, it indicates the expansion valve is functioning normally. If not between the two curves, the expansion valve should be repaired or replaced.

19

1

Share

Where to Check the Tire Date?

The sidewall of the tire (tire side) displays the production date as the last four digits following the DOT code. These four digits are in the format "AABB." The first two digits "AA" indicate the week of the year, while the last two digits "BB" represent the year. Below are situations when tires need replacement: 1. Relying solely on the production date to determine a tire's lifespan is too hasty; actual tire conditions should also be considered. The most obvious sign is the appearance of numerous fine cracks, known as tire cracking. This not only affects the comfort level of the tire but also severely reduces its grip performance, posing a certain danger while driving. Therefore, do not take chances and replace the tire promptly. 2. Additionally, if the tire feels significantly harder than before, it is likely due to advanced aging, especially in hot weather, which accelerates the hardening of rubber products. When this phenomenon occurs, replacement is necessary to avoid the risk of a blowout.

7

3

Share

What does the P0016 fault code mean?

P0016 fault code indicates a malfunction between the crankshaft position and camshaft position. Here are the solutions: 1. First, remove the timing cover to inspect the issue: After removing the timing cover, check whether the belt is broken, skipped teeth, or displaced, and then address the problem accordingly; 2. Check the oil pressure: After removing the timing cover, connect the engine oil pressure gauge to check whether the oil pressure is normal, whether the oil level is at the correct position, and whether the filter screen is clogged; 3. Check the wiring: Then use a multimeter to measure whether the VVT adjustment solenoid valve is damaged, unplug the solenoid valve connector, and use a test light to measure the circuit voltage to detect wiring issues.

19

4

Share

What does it mean when the cruise light is on?

When the cruise light is on, it indicates that the vehicle's cruise control function is activated. Once the electronic cruise system is engaged and the driving speed is set, you can release the accelerator pedal, and the vehicle will maintain the set speed automatically. Although the electronic cruise system is convenient for highway driving, it is recommended not to use it under the following circumstances: 1. The first situation: In heavy traffic or during rain or snow, it is safer to avoid using cruise control. 2. The second situation: Do not activate the electronic cruise system when driving on steep slopes, as significant changes in engine RPM may cause damage to the engine.

9

0

Share

How to Identify the Safety Line on Tire Sidewalls?

Tire sidewall patterns feature a small triangular indicator every 60 degrees. This serves as a directional marker. By following this triangle with your fingers towards the tread surface, you'll generally find two grooves on the tire tread. Inside these grooves, you can feel a transverse line (also visible upon close inspection) - this is the tire safety line. Below are detailed explanations about the tire safety line: 1. The tire safety line functions as a wear limit indicator. When tread wear reaches this line, the tire must be replaced. Otherwise, it becomes prone to overheating and blowouts during normal driving. In rainy conditions, insufficient tread depth reduces water drainage capacity, leading to hydroplaning and loss of vehicle control. 2. If remaining groove depth measures at or below 1.6mm (as indicated by depth markers in the longitudinal tread grooves), the tire requires immediate replacement. At this point, the tire's water evacuation capability is severely compromised, making wet-surface driving particularly hazardous.

14

4

Share

How to Solve the P0340 Trouble Code?

p0340 trouble code solution: Check the camshaft position sensor circuit. Here are the specific solutions: 1. Remove the timing cover to inspect the issue: After removing the timing cover, check whether the belt is broken, has jumped teeth, or has moved, and then address the problem accordingly; 2. Check the oil pressure: After removing the timing cover, connect the engine oil pressure gauge to check whether the oil pressure is normal, whether the oil level is at the normal position, and whether the filter screen is clogged; 3. Check the wiring: Then use a multimeter to measure whether the VVT adjustment solenoid valve is damaged, unplug the solenoid valve connector, and use a test light to measure the circuit voltage to detect wiring issues.

10

1

Share

What is the working principle of an automotive transmission?

What are the symptoms of a faulty expansion valve?

Where to Check the Tire Date?

What does the P0016 fault code mean?

What does it mean when the cruise light is on?

How to Identify the Safety Line on Tire Sidewalls?

How to Solve the P0340 Trouble Code?

What Causes the Engine Belt to Squeak?

What maintenance items are required for a new car at 20,000 kilometers?

What is the working principle of automotive disc brakes?

Wheel Balancing or Four-Wheel Alignment for Steering Wheel Vibration?