E46 - The intermittent wiper problem

[RyanOaks328i]

1999 BMW, 328i. The intermittent wipers work intermittently. Is there a relay that controls the frequency of the wipers? If so, where do I find it and how do I find the part number to order a new one?

The moter works fine always on. The switch is good. Everytime I change the frequency of the intermittent wipers, the wipers make one pass. Sometimes they work again, sometimes the take a very long time to wipe a third time. Sometimes they work just fine for a few minutes, then they just stop working.

[sockethead]

There is a relay but it only operates the speed of the motor (fast or slow) the rest of the functions are controlled by the general module (GM-V) behind the glove box. The general module also controls interior lighting functions, locks, etc. The system will generate fault codes that can be read by BMW diagnostic equipment at the dealer or some independant shops. These codes are different than the ODBII codes that are easly read with a cheap tool.
Actually the general module contains a bunch of relays and some logic. there are some people that will fix the unit rather that replace it. You best bet would be to have the codes read to see exactly where the malfunction is.

[RyanOaks328i]

Any chance the general module (GM-V) also monitors the airbag system?

[psychocandy]

Did you ever figure out the root cause of this issue? I have the exact same problem - intermittent wipers do not work at all under that setting - but when you move the rotary switch up a notch, you get one pass of the wipers.

I was going to just buy another switch off of ebay, but when I saw this post it introduced doubt as to whether that is truly the root cause of the issue.

Thanks

[02325]

please note that the wipers are also speed dependant. car sitting still they dont wipe as fast as cruising the hwy at 50 mph.

no the gm does not control the airbag. it has its own seperate module.

[simonhla]

Did you ever figure out the root cause of this issue? I have the exact same problem - intermittent wipers do not work at all under that setting - but when you move the rotary switch up a notch, you get one pass of the wipers.

I was going to just buy another switch off of ebay, but when I saw this post it introduced doubt as to whether that is truly the root cause of the issue.

Thanks

Mine used to do this too. Do you have the rain sensor? If so it probably isn't working. I'd have to get a new windshield (apparently) to replace my rain sensor so I just took it to my indy shop who deactivated my rain sensors using the diagnostics. What do you know...my intermittent wipers now work as they should.

[02325]

true^^^^^^^^^^^^

[mbcoops]

Mine used to do this too. Do you have the rain sensor? If so it probably isn't working. I'd have to get a new windshield (apparently) to replace my rain sensor so I just took it to my indy shop who deactivated my rain sensors using the diagnostics. What do you know...my intermittent wipers now work as they should.

I'm having my rain sensing wipers deactivated next stop into the dealership. I absolutely hate them, and I want my intermittent wipers to work as they should.

mb

[psychocandy]

Thanks for the good information on the rain sensor. I am almost sure that is my problem as it looks like the original sensor was peeled back and re-attached when the windshield was replaced. It doesn't look like a good clean seal to the windshield.

I am wondering why you have to replace your windshield in order to fix this problem. Can you get a new rain sensor, clean the windshield and re-install?

After more research, it looks like my windshield has the tint across the top and that may inhibit the sensor from working properly. About 20% of the sensor is above the tint line.

[simonhla]

Thanks for the good information on the rain sensor. I am almost sure that is my problem as it looks like the original sensor was peeled back and re-attached when the windshield was replaced. It doesn't look like a good clean seal to the windshield.

I am wondering why you have to replace your windshield in order to fix this problem. Can you get a new rain sensor, clean the windshield and re-install?

After more research, it looks like my windshield has the tint across the top and that may inhibit the sensor from working properly. About 20% of the sensor is above the tint line.

I'm not sure why. That's just what the tech told me and he wasn't looking for the business. There's a little bit of corrosion it looks like between the sensor and the windshield. I'm back there on wednesday so I'll ask for clarification. I also have a tint strip along the top of the windshield. He never said anything about that.

[psychocandy]

I'm not sure why. That's just what the tech told me and he wasn't looking for the business. There's a little bit of corrosion it looks like between the sensor and the windshield. I'm back there on wednesday so I'll ask for clarification. I also have a tint strip along the top of the windshield. He never said anything about that.

http://www.bimmerfest.com/forums/sho...d.php?t=109604

This is where I got my information. Please post next week and advise what you find out.

[simonhla]

Yeah...what i got from that thread is that it is a PITA to remount a rain sensor after it is removed and have it work as it should. I think the rain sensor windshields come with the rain sensor pre mounted form the factory. I'll ask the tech to clarify on wednesday and I'll post what I find. Suffice ot say if you want your intermittent wipers to work anytime soon then you should get the dealership or an indy with the diagnostic tools to deactivate the sensors. That's what i did and quite honestly I don't miss the rain sensors one bit.

I'll still find out what I can for you.

[psychocandy]

Yeah...what i got from that thread is that it is a PITA to remount a rain sensor after it is removed and have it work as it should. I think the rain sensor windshields come with the rain sensor pre mounted form the factory. I'll ask the tech to clarify on wednesday and I'll post what I find. Suffice ot say if you want your intermittent wipers to work anytime soon then you should get the dealership or an indy with the diagnostic tools to deactivate the sensors. That's what i did and quite honestly I don't miss the rain sensors one bit.

I'll still find out what I can for you.

Thanks man, I appreciate the help. If it is as simple as re-installing a new rain sensor, well that seems pretty easy and wouldn't require a new windshield.

Unfortunately, I live in BFE and there is no dealer or Indy shop for a minimum of +1.5 hrs. But if the re-programming turns out to be the best fix I will plan a road trip.

[GixerEd1]

I thought I remember reading somewhere that the Rain-Sensing feature works by measuring the light refraction THROUGH the windshield itself. Light hitting the windshield and passing through it, when within the glass itself, refracts throughout the glass and the rain-sensor measures the amount of light and wipes accordingly. If that is correct, then the rain-sensor is probably not working properly, especially if it's not mounted properly.

[psychocandy]

simonhla> did you find anything definitive out this week in your meeting with the BMW tech?

[simonhla]

simonhla> did you find anything definitive out this week in your meeting with the BMW tech?

I asked him again and he said that to the best of his knowledge you would have to replace the windshield. He just said that they came from the factory like that. He said that you may find an aftermarket company that would re-fit a new rain sensor for you but in his experience these had a patchy record of success at the best. He also said I would probably have to remove the tint strip along the top of the windshield which was likely interfering with it (although in this case not the reason it doesn't work).

Either way it is going to be relatively expensive given the upside. To me it wasn't worth it. I figure if I ever get a crack or chip in my windshield my insurance will pay to have it replaced. In that instance I'll get the rain sensor windshield installed but until then I just deactivated the rain sensor through the diagnostics and use the intermittent function. Works perfectly.

Sorry he didn't give me specific info but I did ask

[psychocandy]

Hey thanks for the good information. Sounds like the best plan would be a dealer re-program. I was looking at my windshield and it appears as if the dealer replaced it just prior to sale. The idiots probably didn't consider the rain sensor. I can still see installation fingerprints on the windshield.

[Critter7r]

Tint will keep the rain sensor from workin, but you don't have to completely remove the tint strip, just trim it around the sensor.

[coolmellowdude]

04 325i E46 Sedan. Got the damaged windshield replaced at SafeLite AutoGlass, returned twice because wiper delay stopped working. Before the second visit, noticed the wipers delay work fine in daylight rain, however, they don't work in night time rain. Second visit replaced with BWM windshield, but still have the same problem. Very strange..

[MarcoZandrini]

To answer the question about the GM5 module and airbags: no, the GM5 has nothing to do with the airbags.