[catness]

I'm having similar issues. Picked up a Limited on Jan 24th, a couple days later I got a notification on the Toyota Connected app that a "window was down". Went outside to check the car, no windows down, went back inside. Next morning the battery was dead. Second time it happened I used the app to lock the van when it told me it was unlocked (i had run an errand and didn't lock it when I got home), the next morning it was dead. Took it in today to the dealer, they checked the battery and claimed it was dying due to short trips plus the extreme cold. Not feeling like that is the correct answer, given that the only times it happened the Toyota Connected app was involved. I feel like it was something to do with the DCM.

 

[pamhar]

I'm having similar issues. Picked up a Limited on Jan 24th, a couple days later I got a notification on the Toyota Connected app that a "window was down". Went outside to check the car, no windows down, went back inside. Next morning the battery was dead. Second time it happened I used the app to lock the van when it told me it was unlocked (i had run an errand and didn't lock it when I got home), the next morning it was dead. Took it in today to the dealer, they checked the battery and claimed it was dying due to short trips plus the extreme cold. Not feeling like that is the correct answer, given that the only times it happened the Toyota Connected app was involved. I feel like it was something to do with the DCM.

We've had -30 C temps and no issues.

Biggest difference is that we have base so no kick sensors, wi-fi, connected app. Are you normally in area with good cell tower reception?

Most likely one or combo of above causing issues.

 

[shersingh]

We have had the same issue. Died 3 times in a month. Was told it is the rear kick sensor issue which they now have disconnected. Certainly would recommend that you ask the dealer

Did this fix your issue ?

 

[JSpallanzani]

My salesperson just called me back this evening because I questioned him about those battery problems on Siennas. For some context, I put a deposit on a 2022 XSE AWD 2 weeks ago and when I tried to test drive the car, the battery was dead in front of the salesperson. That made me search on forums regarding this issue. When I went back to test drive the car, I talked to him about my concerns and initially, he said he heard about one occasion that one of his customer had battery troubles twice but that was all he heard about. I asked him to investigate further because of what we read on forums online. Well he called back and he said he was told that approximately 50% (!!) of all Siennas presently sold here (Quebec, Canada) have battery problems and that apparently Toyota is aware and trying to find a fix to the problem. The dealership management suggested to use the Comfort package ($$) (battery heater or charger) to completely avoid this problem until the fix is found. So it definitely seems to be a very common issue.

 

[wscan]

I'm having similar issues. Picked up a Limited on Jan 24th, a couple days later I got a notification on the Toyota Connected app that a "window was down". Went outside to check the car, no windows down, went back inside. Next morning the battery was dead. Second time it happened I used the app to lock the van when it told me it was unlocked (i had run an errand and didn't lock it when I got home), the next morning it was dead. Took it in today to the dealer, they checked the battery and claimed it was dying due to short trips plus the extreme cold. Not feeling like that is the correct answer, given that the only times it happened the Toyota Connected app was involved. I feel like it was something to do with the DCM.

I doubt it is due to short trips. In a non-hybrid that tends to be an issue, since it requires a large amount of power to start the car. It takes the alternator some time to replenish the energy consumed by the starter. In the hybrid, the battery just powers the computers that run the car. The engine is started using power from the traction battery. So there is no large consumption of energy when the car is started. In addition, the Sienna battery is smaller requiring less time to get to a full charge. So far, the battery drains have been traced to the DCM (2021 models primarily) and the kick sensors (2022 models).

 

[sierwronski]

Curious what would have changed from 2021 to 2022 models that results in the kick sensor problem showing up in 2022. Pretty much figured there the same vehicle.

 

[Irish1812]

Got a call back from Toyota this morning, they had my Sienna for 1 week to do some test and the best Toyota Canada engineer was at my dealer yesterday. They finally found the problem that some people here already mentioned (Kick sensors) Technical advisor told me that Toyota will release a fix in the coming weeks and for now they disabled all kick sensors. I will finally get back my Sienna this afternoon and waiting for a permanent fix!

 

[Sienna9816]

Curious what would have changed from 2021 to 2022 models that results in the kick sensor problem showing up in 2022. Pretty much figured there the same vehicle.

May be the number of users? Last winter was the first one for this Gen. I suppose a lot fewer users last winter didn't cause all possible issues to bubble up until now?

FWIW, sitting in the car with lights and music on for about 15 minutes is enough to trigger the Low battery symptoms. I had it happen to us this week when kids got to it 15 minutes before I did. They got the ACC on for music. When I tried to get it going, I got the parking brake message. Luckily, cycling it off and on got me going again. Temperature was in 30s.

 

[JSpallanzani]

Got a call back from Toyota this morning, they had my Sienna for 1 week to do some test and the best Toyota Canada engineer was at my dealer yesterday. They finally found the problem that some people here already mentioned (Kick sensors) Technical advisor told me that Toyota will release a fix in the coming weeks and for now they disabled all kick sensors. I will finally get back my Sienna this afternoon and waiting for a permanent fix!

This is very encouraging!

 

[sierwronski]

Just got out of our dealer for my 10,000 mile check. I had mentioned when scheduling of my most recent overnight battery drain. Said there was a lot of chatter about door sensors and asked them to disable mine. They said they could not get the sensors disabled as my appointment was for the 10,000 mile service and there are no service bulletins. I pleaded with them to do whatever was easy to disable sensors to no avail. When I picked it up, I literally disabled all sensors in less than a minute myself using dashboard control panel for settings. Pretty disappointed. We'll see if it eliminates the battery drain. Let me know if you need guidance on how to disable sensors.

 

[Greddy2000]

Got a call back from Toyota this morning, they had my Sienna for 1 week to do some test and the best Toyota Canada engineer was at my dealer yesterday. They finally found the problem that some people here already mentioned (Kick sensors) Technical advisor told me that Toyota will release a fix in the coming weeks and for now they disabled all kick sensors. I will finally get back my Sienna this afternoon and waiting for a permanent fix!

Did the engineers give an explanation to why the kick sensors only started to drain the battery when winter started?

 

[pamhar]

Did the engineers give an explanation to why the kick sensors only started to drain the battery when winter started?

Perhaps due to being covered with ice/snow/mud.

 

[Tfk]

Got a call back from Toyota this morning, they had my Sienna for 1 week to do some test and the best Toyota Canada engineer was at my dealer yesterday. They finally found the problem that some people here already mentioned (Kick sensors) Technical advisor told me that Toyota will release a fix in the coming weeks and for now they disabled all kick sensors. I will finally get back my Sienna this afternoon and waiting for a permanent fix!

Whereabouts in Canada are you?

 

[wscan]

May be the number of users? Last winter was the first one for this Gen. I suppose a lot fewer users last winter didn't cause all possible issues to bubble up until now?

FWIW, sitting in the car with lights and music on for about 15 minutes is enough to trigger the Low battery symptoms. I had it happen to us this week when kids got to it 15 minutes before I did. They got the ACC on for music. When I tried to get it going, I got the parking brake message. Luckily, cycling it off and on got me going again. Temperature was in 30s.

My Sienna was at the dealer yesterday. I happened to be at the car to discuss something with the tech. I noticed that they had a NOCO jump starter attached under the hood. I guess they have found that it is easy to run down the hybrid batteries while working on the vehicles, so they keep the battery charged with the NOCO. I did see that the battery voltage was running at 12.8 volts or so all the way home, which indicates the battery had a full charge. When the battery needs to be charged, the voltage runs about 14.4.

 

[Tfk]

My Sienna was at the dealer yesterday. I happened to be at the car to discuss something with the tech. I noticed that they had a NOCO jump starter attached under the hood. I guess they have found that it is easy to run down the hybrid batteries while working on the vehicles, so they keep the battery charged with the NOCO. I did see that the battery voltage was running at 12.8 volts or so all the way home, which indicates the battery had a full charge. When the battery needs to be charged, the voltage runs about 14.4.

Just curious, why would the voltage be higher if it neeeds to be charged?

 

[JohnHartshorn]

Just curious, why would the voltage be higher if it neeeds to be charged?

It's not that the voltage on the battery is higher, but rather the alternator is charging the battery. I noticed this first on my 2018 Silverado. If the battery is charged, the alternator turns off, and voltage drops to the batteries ~12v. When the alternator kicks back in, the voltage jumps to it's output of ~14v.

 

[wscan]

Just curious, why would the voltage be higher if it neeeds to be charged?

As with many current cars, the charging voltage varies with the charge level of the battery. Once the battery is charged, the charging voltage is lowered to prolong the life of the battery (not overcharging it) and to marginally increase fuel mileage (CAFE targets are very important to manufacturers and every little bit helps.) Essentially, 14.4 volts is the charging voltage and 12.8 volts is the maintenance voltage.

 

[Tfk]

It's not that the voltage on the battery is higher, but rather the alternator is charging the battery. I noticed this first on my 2018 Silverado. If the battery is charged, the alternator turns off, and voltage drops to the batteries ~12v. When the alternator kicks back in, the voltage jumps to it's output of ~14v.

But there’s no alternator in the Sienna.

 

[JohnHartshorn]

But there’s no alternator in the Sienna.

No conventional alternator. The 12v battery charges from the high voltage battery. If the 12v battery is fully charged, the charging system turns off.

 

[DCorbett]

Having the discharge issue on my 2022 sienna limited. Happens randomly, 4 times in 3 months. Just parking it overnight and coming back the next day it can be dead. Dealer has had it twice, replaced the 12v battery. Still happens. Not sure about the first two times, but the last two times it died after driving through snow and parking overnight. I grab a meter and check voltage in the battery in the mornings now. Most days it's acceptable 12.4-12.6v (should be more like 12.8v), on "dead" days it's 11.7v or less. A few days ago, I measured 11.7 and it was too dead to start...told me I wasn't pushing the brake pedal...so some sensor or controller wasn't getting enough voltage to function. As soon as I gave it a boost from a charger, everything powered right up.