# Toyota Sienna 2012 - What is this part? **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [October 21, 2020, 8:57pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446 "2020-10-21T20:57:14Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![cmil14](https://avatars.discourse-cdn.com/v4/letter/c/3ec8ea/32.png) [@cmil14](https://community.cartalk.com/u/cmil14)\ **Post date:** [October 21, 2020, 8:57pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/1 "2020-10-21T20:57:14Z")
![Capture](https://global.discourse-cdn.com/cartalk/original/3X/1/6/16c501b706c4748cdd6b23aa0855fd0cfff7a772.jpeg) I have a squeaking sound that appears to be coming from this part. Can someone help me identify what this part is? Any help is greatly appreciated. Thanks in advance! ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/48514_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [October 21, 2020, 9:04pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/2 "2020-10-21T21:04:17Z")
That appears to be the hydraulic control unit for the ABS. Is the ABS warning light lit up? ---
**Author:** ![cmil14](https://avatars.discourse-cdn.com/v4/letter/c/3ec8ea/32.png) [@cmil14](https://community.cartalk.com/u/cmil14)\ **Post date:** [October 21, 2020, 9:28pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/3 "2020-10-21T21:28:34Z")
That looks to be it! No, the ABS light is not on in the car. Is there any component in this that might squeal? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [October 21, 2020, 9:49pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/4 "2020-10-21T21:49:14Z")
Is the noise constant? When does it make the noise? ---
**Author:** ![cmil14](https://avatars.discourse-cdn.com/v4/letter/c/3ec8ea/32.png) [@cmil14](https://community.cartalk.com/u/cmil14)\ **Post date:** [October 21, 2020, 9:50pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/5 "2020-10-21T21:50:16Z")
The noise is mainly when turning on the car for the first time. It seems to go away after driving for a bit. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/48514_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [October 21, 2020, 10:01pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/6 "2020-10-21T22:01:26Z")
Did you just acquire this vehicle? I ask because ABS-equipped vehicles go through an automatic ABS self-test when they are driven after being shut-off for many hours. This varies considerably from one make or model to another, but on some models, that ABS self-test can be fairly noisy. Typically, the noise is heard after driving… maybe… 20 or 30 feet, and will not be heard again until the next “cold start”. ---
**Author:** ![thegreendrag0n](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/thegreendrag0n/32/9265_2.png) [@thegreendrag0n](https://community.cartalk.com/u/thegreendrag0n)\ **Post date:** [October 22, 2020, 3:53pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/7 "2020-10-22T15:53:55Z")
good guess from @VDCdriver, but I would suspect something more simple, like a worn serpentine belt in need of replacement ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [October 22, 2020, 3:58pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/8 "2020-10-22T15:58:02Z")
I agree, that part is near the belt drive area on the passenger side (it’s far away from the brake master cylinder). ---
**Author:** ![cmil14](https://avatars.discourse-cdn.com/v4/letter/c/3ec8ea/32.png) [@cmil14](https://community.cartalk.com/u/cmil14)\ **Post date:** [October 22, 2020, 6:05pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/9 "2020-10-22T18:05:28Z")
We bought it about 6 months ago, but recently had to change the battery and alternator. Not sure if this could have reset something? I took it out today for a drive and the sound seems to come back every time I accelerate. It isn’t overly loud, but the sound is still there. Does that help? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [October 22, 2020, 6:08pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/10 "2020-10-22T18:08:56Z")
It could be an idler for the belt that drives the alternator, or your new alternator could have noisy bearings. Did the noise start when you had the alternator replaced? ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [October 22, 2020, 6:47pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/11 "2020-10-22T18:47:04Z")
The ABS self test occurs at low speed just after starting to move forward for the first time. My 2005 Accord did it, it only first thing in the morning. I backed about 75 feet to the street, put it in drive, and by the time I hit about 10 mph, the test ran. I don’t notice it on my 2017 Accord or my wife’s 2019 Odyssey. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/48514_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [October 22, 2020, 7:48pm UTC](https://community.cartalk.com/t/toyota-sienna-2012-what-is-this-part/171446/12 "2020-10-22T19:48:41Z")
> [@cmil14](#): > > the sound seems to come back every time I accelerate Then it isn’t the ABS self-test that you are hearing. Both of the suggestions below are worth pursuing, as I think that they are the most likely. > [@thegreendrag0n](#): > > I would suspect something more simple, like a worn serpentine belt in need of replacement > [@texases](#): > > It could be an idler for the belt that drives the alternator, or your new alternator could have noisy bearings.