Fault 1
a 2008 annual output of FAW – Volkswagen Magotan 1.8TSI car, users complained that the car sometimes air conditioning refrigeration, air blower and sometimes does not work.
On inquiry car breakdown maintenance records, I learned that the car has been repaired and therefore fault once. The time service condition, the connection failure diagnostic VAS5052 maintenance personnel take the car for each control unit detects the vehicle, the system prompts V2 motor malfunctions. In the simultaneous detection of hand shaking blowers, blower sometimes find work, sometimes do not work, suspect a problem with the blower itself, so the replacement of the same type blower. After standing air conditioning test, the fault does not occur again.
appears similar to the failure of the previous symptoms, according to the last car repair situation, we can exclude the possibility of the blower itself the problem. Since the blower itself is not a problem, we need to focus on issues related to the line to check its aspects. According to the author’s experience in the maintenance, for this failure should check the main problems of power supply and grounding. They then measured using a multimeter blower control unit of the supply voltage, and found that the supply voltage is unstable.
The circuit diagram of magotan seen, the supply air blower (5OA) provided by the fuse of the E-BOXF29. So I found the upper left of a 50 A fuse, after careful examination revealed that the fuses have ablation phenomenon. After careful observation, it can determine whether the fuse fuse connector ablation is caused by virtual access.
FIG 1
After the processing of the fuse connector (FIG. 1) and exchanging the fuse, again measure the supply voltage of the blower, is very stable, Troubleshooting.
Summary: In the course of routine maintenance, we have encountered many cases of such failure. For such a fault the supply voltage instability caused fuse virtual connection, since the electrical component of modern large-scale production process is generally not easily damaged, and therefore does not have to rush to replace parts. But should find a circuit diagram of the power supply and the grounding point corresponding to the measurement of the supply voltage of the corresponding elements, is properly grounded.
Fault 2
a 2008 annual output of FAW – Volkswagen Jetta 1.6 L car, mileage is 55,000 km, the userIt does not reflect the driver side glass lift.
After receiving the vehicle, as determined by the user of the fault test. Left front window regulator motor does not operate, the other 3
Motor door lifter can be normal operation. Based on past experience in the maintenance of such a failure in the car is easier Sagitar one kind of failure occurs, the fault point is generally integrated on a plurality of integrally with the door glass lifter motor control unit. Connection detecting the vehicle fault diagnostic apparatus, the device displays the fault code ldquo; electric window lifter motor mdash; mdash; driver side mdash; mdash; V147 electrical circuit has a fault, power window lifter motor mdash; mdash ; driver side mdash; V147 is not the basis for setting / or do not match correctly. After the service personnel replace the window regulator motors, test failure remains.
FIG. 2
Now the relevant circuit diagram of the I measurement window regulator motor supply line, found in a normal battery voltage. Based on past experience in the maintenance, only the voltage is measured with a multimeter can not determine whether the normal power supply line, because if there is a virtual circuit, a voltage block is not detected by the multimeter. In order to determine whether the power supply is a reliable, low-power I got test light detected, the test found that light does not shine. Thus proving that the entry fault lies in the supply line. After further search, I found that this rail car has broken (FIG. 2) where the driver side door to the vehicle body connection. At this point, the point of failure to find.
the re-wrap the wire harness, window lifter test function returned to normal, troubleshooting.
Summary: FAW – Volkswagen Jetta sedan on the door harness breakage few cases have appeared to provide our service counterparts in the maintenance of this failure, first targeted to be checked. The car’s fault, although not difficult, but requires maintenance personnel in supply reliability of power line inspection needs to have the right approach. Only maintenance experience and knowledge of control theory to master combine together in order to quickly and accurately identify the point of failure.
(Liu Books)