Wiper Issue in MIST Mode – Random 1 to 6 Swipes (2022 Sienna)

[huey123]

Hi everyone,

I’m having a frustrating issue with my 2022 Toyota Sienna that I hope someone here can help me figure out.

Whenever I use the wiper in MIST mode (just a single up-flick of the stalk), the wipers are supposed to swipe once—but instead, they randomly swipe between 1 and 6 times. Sometimes it works correctly, but other times it goes crazy. It happens more frequently when it's raining, but it’s hard to reproduce at a repair shop because when it’s dry, the wipers often behave normally.

I didn't "flick it" too hardi, I would push up on the controller to the “Mist” option and it would go 1 -6 times randomly instead of the usual 1. and when i would put it on “INT”, it would also go 1 or 6 times as if it was set to the LO setting, but it wasn’t. then a few times the blades would just stop in the middle of the windshield.

This makes it nearly impossible to get it diagnosed or repaired, since it's an intermittent problem. And when you just want one swipe and it goes six times, it's incredibly annoying—honestly driving me nuts.

Has anyone experienced this before? Could it be a faulty stalk switch? A control module issue? Something else entirely?

Any insight, similar experience, or even suggestions for how to reproduce it reliably for a tech would be super helpful.

Thanks in advance!

 

[dishdude]

Does this have automatic wipers?

 

[huey123]

Does this have automatic wipers?

No, it doesn't have auto wipers.thanks for your reply.

 

[shortyb]

Rain sensor at windshield usually controls speed/frequency of wipers in intermittent (mist as you call it) mode. Depending on the amount of rain hitting the sensor can cause it to swipe slow, or crazy fast as you've experienced. Lots of vehicles fitted with this now. There should be some kind of switch/setting you can adjust to change the frequency. Check the owner's manual.

 

[JavierH19]

No, it doesn't have auto wipers.thanks for your reply.

I'd double check because you say It happens more frequently when it's raining and that's how auto rain sensing systems behave since I have two so that may be it. What trim level is your sienna. it says the higher trims have it but I imagine some package can include it on a lower trim. Does your sienna stalk look like this? if it does move the stalk to the intelligent position then spray the windshield with a hose.

 

[huey123]

Rain sensor at windshield usually controls speed/frequency of wipers in intermittent (mist as you call it) mode. Depending on the amount of rain hitting the sensor can cause it to swipe slow, or crazy fast as you've experienced. Lots of vehicles fitted with this now. There should be some kind of switch/setting you can adjust to change the frequency. Check the owner's manual.

Rain sensor at windshield usually controls speed/frequency of wipers in intermittent (mist as you call it) mode. Depending on the amount of rain hitting the sensor can cause it to swipe slow, or crazy fast as you've experienced. Lots of vehicles fitted with this now. There should be some kind of switch/setting you can adjust to change the frequency. Check the owner's manual.

Thanks, The owner’s manual says that turning the MIST once will make the wipers swipe once.

 

[huey123]

I'd double check because you say It happens more frequently when it's raining and that's how auto rain sensing systems behave since I have two so that may be it. What trim level is your sienna. it says the higher trims have it but I imagine some package can include it on a lower trim. Does your sienna stalk look like this? if it does move the stalk to the intelligent position then spray the windshield with a hose.

View attachment 287598

Thank you very much for your reply,My trim is the LE base model, and it doesn’t have automatic wipers. It does look the same as in your picture, but there isn’t an intelligent position.

 

[CharBaby]

Your Sienna wouldn't still happen to be under the 3/36 Basic Warranty would it?

 

[JavierH19]

Thank you very much for your reply,My trim is the LE base model, and it doesn’t have automatic wipers. It does look the same as in your picture, but there isn’t an intelligent position.

Sounds like the module that controls the wiper speed. I'm looking up photos of a Toyota sienna front windshield wiper relay module and I'm seeing used prices from 40 to 100 bucks likely from ones pulled out of parted out cars. Not a simple looking relay either, here's an example.

Think you could get a cheap rental sienna?

https://ahparts.com/buy-used/2022-t...PKckyBJwXSSl8soJZ6q9S3s1yOZHPK7WOvh5_9AWFbnuE

 

[huey123]

Your Sienna wouldn't still happen to be under the 3/36 Basic Warranty would it?

Thanks for the heads-up, but sadly it’s already over 60,000 miles

 

[huey123]

Sounds like the module that controls the wiper speed. I'm looking up photos of a Toyota sienna front windshield wiper relay module and I'm seeing used prices from 40 to 100 bucks likely from ones pulled out of parted out cars. Not a simple looking relay either, here's an example.

Think you could get a cheap rental sienna?

https://ahparts.com/buy-used/2022-t...PKckyBJwXSSl8soJZ6q9S3s1yOZHPK7WOvh5_9AWFbnuE

I think this is probably the closest to the real issue. Thanks a ton for pointing it out! I think I’ll try to find a video showing how to replace this part and check it out. Right now, I’m thinking either the relay’s messed up or the wiper motor’s bad, but I can’t really tell which one it is

 

[huey123]

Sounds like the module that controls the wiper speed. I'm looking up photos of a Toyota sienna front windshield wiper relay module and I'm seeing used prices from 40 to 100 bucks likely from ones pulled out of parted out cars. Not a simple looking relay either, here's an example.

Think you could get a cheap rental sienna?

https://ahparts.com/buy-used/2022-t...PKckyBJwXSSl8soJZ6q9S3s1yOZHPK7WOvh5_9AWFbnuE

I finally found the installation location of this part. Although I suspect it’s the most likely cause of the problem, replacing it requires removing the dashboard, which is too difficult.

 

[JavierH19]

Seriously the dash needs to be removed? Man that's some bad luck.

 

[huey123]

Seriously the dash needs to be removed? Man that's some bad luck.

 

[Marcozi]

I think this is probably the closest to the real issue. Thanks a ton for pointing it out! I think I’ll try to find a video showing how to replace this part and check it out. Right now, I’m thinking either the relay’s messed up or the wiper motor’s bad, but I can’t really tell which one it is

The motor is fine. It's whatever controls the motor that's the issue.

 

[huey123]

The motor is fine. It's whatever controls the motor that's the issue.

Thanks, There are quite a few components in the control system. I only know about the stalk switch, BCM, and relay so far

 

[KrisZ]

Has it always done it, or is it a recent development?

I would start with the wiper stalk. From your description of how you use it, it sounds pretty rough.

 

[huey123]

一直都是这样吗，还是最近才出现的？

我先从描述雨刷杆开始。从你的使用方法来看，它听起来很粗糙。

Has it always done it, or is it a recent development?

I would start with the wiper stalk. From your description of how you use it, it sounds pretty rough.

Before, MIST would sometimes wipe twice, but after I changed the blades it got worse—it’ll now do 1 to 6 wipes randomly when it rains.

 

[KrisZ]

Before, MIST would sometimes wipe twice, but after I changed the blades it got worse—it’ll now do 1 to 6 wipes randomly when it rains.

There is now way changing wiper blades would affect anything on the control or electrical side.

You’ve mentioned the wipers seem to be acting weird more when it rains, that could point to a poor connection or damaged wires.
I would remove the windshield cowl and check all connections going to the wiper motor as well as the wiring harness.

 

[huey123]

There is now way changing wiper blades would affect anything on the control or electrical side.

You’ve mentioned the wipers seem to be acting weird more when it rains, that could point to a poor connection or damaged wires.
I would remove the windshield cowl and check all connections going to the wiper motor as well as the wiring harness.

Yeah, every time it rains the problem gets worse, but yesterday when it rained, it didn’t happen as often. Most of the time it was actually working fine.I found a video on how to open the windshield cowl. I’ll take it apart and check. Thanks for your advice!