Wipers with a mind of their own

TBarney

'17 CX-5 AWD GT Prem. Original owner of 91 Miata.
:
Atlanta metro
Picked up a '17 GT w/ Prem Package a few weeks ago and am still figuring things out, but I think I've got an actual problem here, wondering if anyone else has seen it and possibly has a resolution:

First couple of weeks I had the car, wipers were set to "Rain Sensing = ON" and they worked OK. This is the second car we've had with this feature, and I usually get irritated after a while because they never seem to find the sweet spot. I did notice that they didn't really seem to respond to the sensitivity dial.

Doing some reading here, I figured out that Rain Sensing can be turned OFF, and they'll work like regular intermittent wipers. So the last good rain, I did that.

And that's when the problems started. The wipers now go off randomly. Here are the things I've witnessed:
- Bump the stalk up for single wipe, and the wipers swipe 2-3 times.
- Turn the wipers to Intermittent, on the slowest setting, and the wipers swipe 2-3 times, then pause for a while, then swipe once, then pause for a different period of time, then swipe a couple of times, then pause...it's very random and not at all in any kind of steady rate.
- Twisting the dial for a faster period doesn't seem to change anything.
- Turn the wipers OFF (yes, I'm sure it was the off position) and the wipers swipe 2 times, pause, swipe another 2-3 times, then finally quit.
- Started the car after it sat all day at work, wipers OFF (dry windshield) and the wipers swipe 2 times then stop.
- Been dry since then and the wipers have stayed OFF the last couple of times I've driven.

Don't know if I've got a bad switch, or a bad control unit (FBCU? RBCU?) or some other element. It's not clear to me from the wiring diagrams just where this problem is likely to originate.

I'm out of bumper-to-bumper warranty, so I'll pay for this repair, but I'd rather have some idea what it's going to be, if possible.

I'm really hoping there's just some kind of reset I can do, but I don't know that would be...

Help?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Picked up a '17 GT w/ Prem Package a few weeks ago and am still figuring things out, but I think I've got an actual problem here, wondering if anyone else has seen it and possibly has a resolution:

First couple of weeks I had the car, wipers were set to "Rain Sensing = ON" and they worked OK. This is the second car we've had with this feature, and I usually get irritated after a while because they never seem to find the sweet spot. I did notice that they didn't really seem to respond to the sensitivity dial.

Doing some reading here, I figured out that Rain Sensing can be turned OFF, and they'll work like regular intermittent wipers. So the last good rain, I did that.

And that's when the problems started. The wipers now go off randomly. Here are the things I've witnessed:
- Bump the stalk up for single wipe, and the wipers swipe 2-3 times.
- Turn the wipers to Intermittent, on the slowest setting, and the wipers swipe 2-3 times, then pause for a while, then swipe once, then pause for a different period of time, then swipe a couple of times, then pause...it's very random and not at all in any kind of steady rate.
- Twisting the dial for a faster period doesn't seem to change anything.
- Turn the wipers OFF (yes, I'm sure it was the off position) and the wipers swipe 2 times, pause, swipe another 2-3 times, then finally quit.
- Started the car after it sat all day at work, wipers OFF (dry windshield) and the wipers swipe 2 times then stop.
- Been dry since then and the wipers have stayed OFF the last couple of times I've driven.

Don't know if I've got a bad switch, or a bad control unit (FBCU? RBCU?) or some other element. It's not clear to me from the wiring diagrams just where this problem is likely to originate.

I'm out of bumper-to-bumper warranty, so I'll pay for this repair, but I'd rather have some idea what it's going to be, if possible.

I'm really hoping there's just some kind of reset I can do, but I don't know that would be...

Help?
I’d try to switch the rain-sensing feature back on and see, or turn the feature on and off several times with ignition ON without engine running. Also, find out if the windshield had been replaced if there’s any service records you can trace, or check the imprint mark on the lower driver side and see if there’s Mazda logo in it. You may try to remove negative battery post for a “reset”. If everything fails, I’d just set the rain-sensing feature on and hopefully it’d behave like before you did setup change.
 
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