Case 1
Failure phenomenon: a 2007 annual Buick Excelle sedan, equipped with a 1.6 L engine, manual transmission, mileage 26000 km. This car is a car accident, difficulty starting the engine after the repair, maintenance repair shop after several fruitless, by a friend dragged me plant.
Check Analysis: after the vehicle to plant, after a preliminary examination, the ignition system is normal, but no fuel injection pulse signal. Connection failure detecting diagnostic X-431 engine control system, only one fault code, meaning that the gas mixture ratio errors. We believe this DTC fault diagnosis is not much reference value. After checking the Buick Excelle original maintenance manual, found a high voltage but there is no possible causes of the fault injection pulse 2: ① the original car alarm is activated; ② engine during starting, open the throttle in the full load position, engine the control unit issues an instruction off oil.
According to these prompts, diagnostic connected again, read DTCs found no fault alarm. Observation data flow engine, found not step on the accelerator pedal, the throttle opening degree is the percentage of 97, data is not changed accelerator pedal is depressed. Check the throttle and the relevant line, found plug connector throttle position sensor and air pressure switch inserted misplaced. Exchange plug, connect the original car lines in the correct way, start the engine, the car smoothly, troubleshooting.
Case 2
Failure phenomenon: a 2009 annual Buick Excelle sedan, equipped with a 1.6 L engine, manual transmission, mileage 21000 km, ABS lights during emergency braking, the left front wheel Hugging.
Check Analysis: User reflect new car just replaced pump ABS, ABS is a previously failed lights, diagnostic can not communicate. First connect diagnostic fault code read, stores a meaning ldquo; left front wheel brake opening time is long rdquo; fault code. After clearing the fault test code, with the data stream read, normal speed of four wheels, but now the left front wheel brake lock, ABS lights. Lifting vehicle wheels 4 are rotated, the rotation is normal to observe. Because it is new for the ABS pump, so the inspection focused on this part. Check the ABS pump line plug without exception, and then check the brake lines, under which discovered the problem, it turned out to be the left front wheel and master cylinder tubing reversed.After the pipeline replacement, troubleshooting.
Review Summary: The above is purely man-made failures, repair work in your care. Maintenance personnel to strengthen the study of the principles of the vehicle structure, repair and develop good habits. From this example two troubleshooting we can see from the analysis start! So as not to make detours.
(Zhang Baojun)