Transmission fault diagnosis and usage

Have you ever encountered a situation where the gearbox cannot be shifted or jumped? Many people may think that driving an automatic car is easy, as long as they will refuel, loosen oil, and brake. However, the incorrect use of automatic transmissions can easily damage the transmission. This edition of the “Owners’ Classroom” will teach you how to judge the fault and use the automatic transmission correctly.

Symptoms

Faults show up

The automatic transmission is just like the human body. When the body is uncomfortable, there will always be some external performances. Then what performance should we use to judge whether the transmission has malfunctioned? The reporter interviewed relevant professional technicians and listed the following 8 typical transmission failure performances. If the following conditions occur, it indicates that there are problems with the vehicle. Most of the reasons are related to the gearbox and need to be repaired in a professional 4S shop.

Phenomenon 1. When the gear is engaged, the gear cannot enter the gear smoothly.

Phenomenon 2. Release the brake more than 1 second after the gear is engaged. The vehicle will not run automatically due to fatigue.

Phenomenon 3. The speed is not good. After rising to a certain speed, step on the throttle and accelerate.

Phenomenon 4. When the gearbox shifts, the gear cannot be disengaged.

Phenomenon 5. The gearbox automatically disengages or disengages.

Symptom 6. Excessive vibration after gearing or during driving.

Phenomenon 7. In a smooth ride, the engine speed suddenly rises and the engine power output suddenly interrupts.

Phenomenon 8. Abnormal sounding of the gearbox. The sound is noticeable under the front of the gearbox and under the oil pan.

Prevention articles

In addition to symptomatic remedy, it is more important to prevent the problem before it occurs. If the gearbox is really out of order, it can only go to a professional 4S shop to “see a doctor”. Repairing boxes is expensive, and it is more sensible to prevent it from getting sick than to see a doctor.

Misuse of errors

In the driving process of automatic transmission models, the habitually incorrect operation will reduce the service life of the transmission. The following sections will focus on the areas where automatic transmissions are more prone to misunderstandings during use.

Myth 1. When the vehicle is parked for a long time, the shift lever is still hung in the D range.

When waiting for a signal or traffic jam, if the time can maintain the shift lever in the D range within one minute, but for a long time, it is better to swap in N (neutral) and tighten the parking brake, otherwise it will The oil temperature of the transmission is increased, and the oil is easily deteriorated.

Myth 2. When driving at high speed or downhill, shift the shift lever and slide it in the N range.

In order to save fuel, some drivers shift the shift lever to N-block to coast when driving at high speed or downhill, which is likely to burn the transmission. When the long slope is actually required to slide, the shift lever can be kept in the D block, but the engine can not be turned off.

Myth 3. Start the engine in gears other than the automatic transmission P or N.

Starting the engine outside the range of P or N, although the engine is not running, it is possible to burn out the neutral start switch of the transmission. Therefore, the engine can only be started in P or N range. Before starting the engine, make sure that the shift lever is in P or N range.

Misunderstanding 4. The parking brake is not used when the ramp is parked.

When parking on the slope, there is a potential safety hazard if the parking brake is not used. Although the parking lock mechanism provided in the P position of an automobile equipped with an automatic transmission is generally seldom ineffective, it may cause accidents if it fails. .

Myth 5. As long as the D block starts, the throttle can be increased to high gear.

This practice is wrong. Because the shift operation should be "advanced early-advanced throttle, step on the throttle down ahead of schedule." That is, after the start of D block, keep the throttle opening 5%, accelerate to 40km / h, fast loose throttle, can be increased to a gear, and then accelerated to 75km / h, loose throttle can increase a gear. When driving down, press the driving speed and press the throttle slightly to return to the low gear. However, it must be noted that the throttle must not be stepped on. Otherwise, the low gear will be forcibly engaged and the transmission may be damaged.

Maintenance inspection and oil change are the key

Automatic transmission models do not strictly comply with maintenance regulations during use. Lack of timely inspection and routine maintenance will accelerate the formation of damage and failure of the transmission, and even increase the danger of failure consequences. Therefore, preventive maintenance will be necessary. The detection and replacement of lubricant ATF is very important.

1. Pay attention to the oil level (in case of hot car inspection), check whether there is oil leakage, transmission oil can neither be too much nor loss, the loss may cause the burning of the box, too much will cause the transmission to overheat;

2 pay attention to maintenance and oil change, each car manufacturer produces different brands of cars, oil change cycle is not the same, pay attention to their own brand of operating instructions, expired must be replaced, and some cars must add the company's oil, otherwise it will Enter the emergency mode, the situation of the lock third gear;

3. Check the color of the gearbox oil at any time. The normal transmission oil should be odorless, translucent, red or yellow. If the gearbox oil is found to be black or burnt, it must be replaced immediately.

Major brand oil change cycle and price

Shanghai Volkswagen: Change ATF every 60,000 kilometers. Replace ATF oil costs about 1600 yuan. If ATF is thick and smelly, the cost of maintenance and repair should be between 10,000 and 20,000 yuan.

Ford: Check every 40,000 kilometers and replace ATF every 60,000 kilometers. Replacement of domestic vehicles ATF oil, the cost of 600 yuan; imported cars need to replace the filter, the price is slightly higher, at 800 yuan.

Guangzhou Honda: Change ATF every 60,000 kilometers. However, technicians recommend replacing the ATF every 40,000 kilometers. The cost is about 300 yuan.

Toyota: Replace ATF every 40,000 kilometers. Replace ATF oil costs 700 yuan.

FAW-Volkswagen, FAW Car: Replace ATF every 60,000 kilometers. Jetta, Polaris and Golf automatic models to replace ATF, the cost of 700 yuan. If the use of the car is in poor working condition, it is recommended to replace it 10,000 kilometers in advance and the cost will be around 2,100 yuan.

Dongfeng Citroen: Replace ATF every 60,000 kilometers. The ATFs of Fukang, Elysee, Senna and Picasso should be replaced at 60,000 kilometers and the cost should be around 400 yuan. Replacement of other models will be slightly more expensive.