Car Diagnostic Tool: 八月 2015

2015年8月30日星期日

BMW 535GT sedan accelerated Irregularity

A mileage of about 80,000 km, equipped with N55 engine 2010 BMW 535GT sedan. The car accelerated irregularity.

Check and analysis: Use special car diagnostic tool found the car at 80 km/h speeds, the engine speed 1 700 r/min, it seems to be an invisible force pulling back. When the speed reaches 110 km/h, the engine speed 1 800 r/min, the pull power disappears, but the body appears shake violently. When the vehicle speed reaches 135 km/h, the engine speed 2 200 r/min, the vehicle was transferred to normal driving.

Use cruise control function, set the speed at 110 km/h, the body shake persist. Changed the shift mode of the transmission to sport mode, the engine speed is increased to 2 300 r/min, the body shake disappear.

Under the premise of keep the speed as 110 km/h, take manual mode shift. When 8-speed 1 800 r/min shaking appears, 7-speed 2 300 r/min shake weakened, 6-speed 2 600 r/min shake completely disappeared.

Integrated test results, found shaking occurred mainly at speeds 110 km/h, the engine speed 1 800 r/min. Analyzed this time engine working condition can be seen, since the car driving produced the drag has risen to a certain extent, but the engine speed is lower, so the actual load rate of the engine is larger.

In this case, the engine torque response characteristic is poor, prone to stalling. Since the drag unchanged, slightly increase the speed, the stall phenomenon disappear immediately, that shows the engine intake system is good, the problem is mixed gas combustion bad.

Observed the fuel correction amount data when the car driving, normal, so suspected the fuel quality has problem. Extracting the fuel sample to check, found the color is abnormal, pungent odor, is low quality fuel oil.

Troubleshooting: After replacing the fuel and clean the fuel supply system, remove the adaptive value of fuel correction amount, use BMW ICOM diagnosis no fault code, test the car, confirmed troubleshooting.

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2015年8月19日星期三

Dongfeng Peugeot 307 R range impact caused by the brake band

A 2004 Peugeot 307 2.0 with mileage of about 180,000 km, matching AL4 type electronically controlled 4-speed automatic transmission. This car a month ago had a sense of frustration when lifting gear, transmission fault indicator occasionally lit, after lighting the car driving difficult (should be locked third speed's reason). Because the failure phenomenon is not frequent, so there is no timely maintenance. Continue to use for some time, in recent days when driving fault phenomena become frequent.

Firstly, maintenance staff use lexia 3 pp2000 to diagnose the car control system, in the automatic transmission control system detects the fault code meaning of hydraulic solenoid pressure regulator valve failure. Maintenance staff first check the oil level and oil quality of transmission oil, found oil has gone bad, and accompanied by burning smell, indicating transmission internal friction elements have been burned. Then maintenance staff removed the transmission from car. After dismantling examination, found almost all of the friction plates all burned, also still forward gear worn, brake band broken, reverse gear brake band and brake drum wear and so on phenomena.

Given the burning extent of the automatic transmission, maintenance staff replaced the transmission overhaul package (including friction plates), the main hydraulic solenoid valves, clutch pistons and brake band and other damage accessories, renovation the torque converter and cleaning valve body.

After the work is completed, the transmission assembled in accordance with standard processes. Again use lexia 3 diagnose the car control system, no fault code, test the car, everything is normal, troubleshooting.

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2015年8月9日星期日

Analyzing second - hand car whether have collision accident

Consumers in the selection of second-hand car, always worry about whether there is a big accident. In the selection of second-hand car, in addition to grasp the merits of the key components of the engine, brakes, turn, transmission, electrical equipment, grasp the vehicle once the accident is also very important. While check the frame is a good way to determine the whether have cracking accident.

When choose the second-hand car, must to test drive before you buy, if have the steering uneven and unstable, wheel have ring in the process of straight, tire has abrasion, braking deviation and so on problem happens when you test drive, it may be the frame has been hit deformed caused.

When site inspection of the vehicle, by the following method:

1. Find straight line. Check the right and left side front and rear wheels whether a straight line, if not, that means the overall frame bent.

2. Measurement gap. Measuring the gap of each wheel rear side and wheel cover, should be roughly the same, otherwise explain the frame or whole body with a curved signs.

3. Find traces. look the two rails of the whole cabin, usually not easy to see the bottom of the battery, while the left side is easy to observe.Check them whether have the sign of welding or cracking. If it is rear-end or side-impact accident, the frame will be squeezed then bent or cracked, need welding repair.

4. Find cracking. Check car's fender portion, which is the key part to determine the car whole body whether have accident, if there are traces of welding or cracking, it shows have appeared side-impact accident; If can drive to the trench, you can clearly checked.

If you think these are trouble, you can use car diagnostic tool to detect whether have collision, that is simple and convenient. universal car scanner can works on different brands of vehicles through OBD. You can think it as a powerful PC based car obd2 scanner which can enter in many kinds of cars system and diagnose the problem of car even if make some coding job.