QuestionMy windshield wipers decided to quit working this weekend. Started the car, they wouldn't turn on. Drove in the rain to buy fuses, replaced wiper fuse (fuse box in engine compartment) and when that didn't work also replaced fuse for fluid (fuse box in car dashboard). Doesn't seem to be a fuse issue. I kept turning off and restarting the car many, many times. One time, the blades "jumped" ever so slightly. Haven't been able to reproduce moment. Before I go to the dealer, what should I know?
AnswerHi, Ginger;
I'm glad you are safe. I hate driving with hampered visibility. Since your car is nearly new, and since there is a "campaign," or "recall" to install covers to protect certain wiper motors, the repair will be free at your local Volkswagen dealer. It sounds like the motor is no longer working at all. Either that or the wiper "transmission" has become disconnected from the motor, or from the wiper arms. If the wiper motor makes noise at all, it is the transmission. However, if there is no noise whatsoever, then it is the motor. There are 2 brands. One is Bosch(big surprise), and the other is Mitsubishi(?)...I can't remember for sure which brand name is on the other variety.
Not withstanding the possibility that the problem is a failure of the CAN bus, or LIN bus communications system on your Passat. CAN means "computer area network." LIN means "local integrated network."
The ECM's talk to each other through a "gateway," and they also oversee the "local users." For example, in the drivers door there is computer, an ECM..."electronic control module"..., that oversees the operation of the electronics installed in the drivers' door, and other places in the car. The "comfort, and convenience module," is an ECM. The door locks, the alarm, the windows, and, in fact the wipers, all receive instructions from the comfort, and convenience "ECM." Have you ever had any other, seemingly unrelated "episodes" with the alarm...., or the windows...., or the door locks? The trunk release, and the gas door solenoid release are other parts of the Comfort Module. All of the 40 or so "ECM's" communicate with one another through the CAN bus system, and "Gateway." The "Gateway" is where we are able to retrieve information, as well, using the VAS 5052, Volkswagen "scan tool." Finally to the point! The LIN bus, or local integrated network sends instructions to the "end users." The LIN bus is what carries the impulses generated by the "Module" to the motors, or solenoids, or switches/relays, or light bulbs, or diodes, or light emitting diodes. So, if the Comfort module is sending a signal that the gateway cannot forward to the LIN bus controlling the wipers, because the signal is corrupted in whatever fashion, then the entire "electrical system" may be perfectly fine, but the computerized communication system may not be able to translate that signal into a viable action. I realize this already too much information, but here's the "kicker." All of the worlds countries have their own "rules of the road." Driving position(right, or left hand drive), lighting(fog lights, back-up lights, license plate lights, or even REAR fog lights, and hazard flashers) are all things that are controlled by these ECM's and depending on the country we happen to be in we can build EXACTLY the same car, with the same number of nuts, and bolts, and devices...I mean EXACTLY the same, but change the programming, or...."coding" of that ECM and make the car legal in Germany, or Finland, or Canada, or the U. S. A. So, if the "coding" of the ECM says one thing, and the "coding " of the wiper motor says a different thing, it would be like me typing in a Cyrillic alphabet, and you trying to comprehend it.
Far too much, I know! Over the top!
Ginger, I hope if you have taken the time to read this whole "treatise" then you have gained an understanding of something you wanted to know. I only hope I didn't bore you, or lose you back there somewhere!
"Jumping" blades is part of the good programming. The wipers are literally programmed to adjust their position slightly to reduce fatiguing the wiper blades to keep them fresher, longer. In fact, after the repair is made, watch the blades more closely, and you will notice that they move ever so slightly every time they are turned off, just to reduce fatiguing the rubber they are made from.
Thanks for trudging through this. Hope it helps.
