Wipers stop mid windshield on 2023.27.7 in heavy rain and no longer mandatory in FSD

[Richt]

Help! This is a safety issue up here I. The Pacific Northwest. Has anyone else had this problem? What’s a fix:

1. I don’t know if it’s software or hardware but we have a 2018 M3P. With FSD 2023.27.7. Never had any wiper problems before.
2. Last week it started really raining. And pulling out I hit the wiper button and the wipers both just open into the extended position and stopped.
3. Even if I hit wash they would stay there and spray fluid. I could move them manually. Down and they would still spray. So the motor was not powered at all.
4. I then noticed that when I moved them up and down eventually it would start wiping again. I tried the two finger reset no good. But somehow after a few times it would start wiping again. Note it was totally stuck. In all wiper modes and in service wiper mode.
5. Another poster mentioned auto wipe is no longer required. And this is true in this car. I don’t know if that’s related.

We then called Tesla service and the next day was nice and sunny and all miraculously worked perfectly fine. He did a hard reset just in case. Checked the motor and it was fine.

So we went off on a three hour drive to Portland:
1. The auto wipers didn’t work at all (I’m wondering is this a front camera malfunction?) during the trip
2. We manually wiped and made it down. And it worked fine for three hours. So doesn’t dell like a bad connection. The rain was zero visibility for hours.
3. Parked the car and had dinner. Then on the way to the supercharger in heavy rain. Same symptom. The wipers extended when I set it to intermittent and then froze up.
4. Tried to manually move them. No motor resistance at all. Like the car thought the motor was in service mode or something.
5. I manually moved them down and nothing happened. Activating wiper service did nothing.
6. Did this a few more times and suddenly it all began to work again.
7. Rain stopped and all was good.
8. Then backing the car out again the at or next stop and the wipers stopped up again. Depowered at the top of their stroke.

Any theories?
1. I guess I could replace the motor assembly. I have an appointment in 48 hours. I’m very willing to do that if necessary
2. Could I guess be a loose connection in the wiper motor as the motor just seems shutoff and unpowered when it stops. Maybe because it’s wet but it seemed to work fine on a long trip.
3. Doesn’t seem like the fuse as it keeps coming back on.
4. I would suspect the firmware but a failure like this with Loss of all wiper function in all modes seems like it would result in massive chatter in this forum :-$

Help! Advice?

 

[Kevy Baby]

From everything you're describing, I say you issue is something that will need to be handled by Service.

 

[Richt]

Yes thanks I’ve learned a few things

1. This latest build under FSD doesn’t allow you turn off the wipers but you can switch from automatic.
2. I agree with you. We finally made it home today by the wiggle the wipers along bootstrap and then setting it on the fastest setting. We ran it all the way back. It does feel like it’s hardware. That is there’s a sort of warmup phenomena. Once it will swing once or twice then stall. But like a model T car. If you leave all the doors closed and surge like hell at fastest speed it stayed on.
3. We made it home and this is prmotlybstalled again. I’m guessing there is a temperature dependent connection problem either with the motor or perhaps the position sensor as it will stall every so often.
4. It also might be that I couldn’t get Tesla wipers (they are sold out) but followed the link to the Bosch equivalents (from this forum) and bought them. I suppose the motor could be stalling out with too much friction
5. Plan is to get Tesla service back. Pay the $400 to replace the motor. Hope they have Tesla blades. And hope it is cold and wet so it fails and we can see if a new motor helps.

Thanks!

 

[jkdman123]

As far as I know, the wipers were never required to be ONLY in auto mode when autopilot is engaged. I could always change them to one of the different wiper speeds (and often did since auto sucks so bad). You just can't select OFF when autopilot is engaged.

 

[Richt]

Yes in older builds, it had to be in auto only AFAIK, but now you just need it not to be off.

And reporting to all...

1. The failure mode for Tesla wiper motors isn't total failure, according to my buddy Jay at Tesla Service, it is that they stop and require a hardware reset to get going and then fail again (check!)
2. He replaced the wiper motors and all is good, thanks all!

I documented what happened in Tesla Wiper Motor Failure and Glovebox Squeaks on my "don't forget thing's Rich blog"

It is a super early build Model 3 Performance delivered September 2018, so not surprising I guess to see a wiper motor failure. We should have just proactively replaced the motor on the first service call. We were all confused (the service guy and us) when the motor just started working again after a hard reset.

This doesn't seem like an actual motor failure (eg the motor burnt out), but something about the control system hardware buried in the thing. Or maybe the reporting circuitry (eg wiper position reporting), but there you have it.

 

[PianoAl]

1. I could move them manually.

2. The auto wipers didn’t work at all (I’m wondering is this a front camera malfunction?) during the trip

Probably not relevant, but those things are consistent with the wipers being in Service Mode.

 

[Richt]

Yes well when I got them manually moved back in. Pressing service mode. Didn’t move them out as it normally would so probably a bad motor. FYI.