Wei Zhi sedan left front door glass can only lift the cab a little distance, while the other window glass lift properly.

4S shop maintenance said failure on the controller. This controller took over the first suspect poor contact of relay K1, K2-contact, after testing, contact is good. Suspect bad resistor R1, R1 resistance is too low and cannot find a substitute, temporarily forget about it. Focus on detection of U2 and related components, are not unusual.

Finally remove the W1 and W2 (W3, W4), contrast foot non-resistance on the road, as a result, two groups of resistance are the same, according to Wl foot functions, W1 related foot-powered and tested separately. Later, do the same experiment with W2, resulting in two sets of test data are exactly the same.

At this point, repair distressed, helpless, had W1, W2, restored car test, results failure miraculously disappeared, do the learning function, automatic lifting and manual lifting, anti-pinch protection, all normal.

This probably went off and a week later, fault appeared again. Analysis of glass can lift a little distance instructions instruction has been issued correctly, but for some reason only to stop action, suspect sense resistor R1 resistance value becomes larger, causing the pressure drop caused by larger, when over the glass to the top and bottom threshold, W1 will mistakenly believe that glass has been running in place, therefore, issue a stop order, the motor off and running.

R1 was hard to find, try R1 and R3 had to be interchangeable, with the result that fault remains. It seems that trouble has nothing to do with the R1 W1 is a distinct possibility of internal circuit damage. Analysis of welding again W1 and W2, again both feet on the ground resistance measurement, as a result, two groups of resistance are the same. Respectively of W1, W2 and foot-powered and tested again. This time, discovered on W1 is the problem.

W1 substitute cannot be found, taking into account the other window lift normally, replace the controller as a whole a pity, therefore, had to Wl, W2 swap. W2 is the right front window control module, its frequency is not high, they can not, after swaps, left front door glass lifting correctly.