# Electronic sound when braking and when shifting into reverse/drive **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** prius, toyota\ **Created:** [July 19, 2020, 8:27pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560 "2020-07-19T20:27:02Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Ryan-119](https://avatars.discourse-cdn.com/v4/letter/r/9de053/32.png) [@Ryan-119](https://community.cartalk.com/u/Ryan-119)\ **Post date:** [July 19, 2020, 8:27pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/1 "2020-07-19T20:27:02Z")
Hi everyone, my 2009 Prius makes a sound similar to what I can best describe as an old computer struggling to complete a task when I either hit the brake or shift into drive or reverse. The sound is not constant, it happens when I begin moving always and when I slow down almost to a stop but never at speed. What could this be? Thank you. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [July 19, 2020, 9:04pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/2 "2020-07-19T21:04:51Z")
Any dash lights light up when this happens? And dash warning lights on all the time? Check engine light? How many miles on this thing? ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [July 19, 2020, 9:14pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/3 "2020-07-19T21:14:09Z")
How long have you owned this Prius? If you have owned it for a long time, is this noise a new phenomenon? If you haven’t owned it for the long term, I am wondering if the noise that you hear when braking is the result of the car’s regenerative braking system being activated. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [July 19, 2020, 9:31pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/4 "2020-07-19T21:31:23Z")
The hydraulic brake pump is noisy. With the vehicle in park, apply the brake several times to see if you can replicate the noise. ---
**Author:** ![rplantz](https://avatars.discourse-cdn.com/v4/letter/r/8c91f0/32.png) [@rplantz](https://community.cartalk.com/u/rplantz)\ **Post date:** [July 19, 2020, 10:19pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/5 "2020-07-19T22:19:07Z")
Any other way you can describe the sound? I’m retired software engineer, been programming them since 1961, but I’ve never heard one “struggling to complete a task.” I’ve heard fan noise (hear it now on my desktop computer) and disk heads moving. I’ve also heard tape drives moving back and forth. ---
**Author:** ![old\_mopar\_guy](https://avatars.discourse-cdn.com/v4/letter/o/6bbea6/32.png) [@old\_mopar\_guy](https://community.cartalk.com/u/old_mopar_guy)\ **Post date:** [July 19, 2020, 10:25pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/6 "2020-07-19T22:25:57Z")
I miss the sound (and visual ) of 9 track tape drives on a 390. ---
**Author:** ![Ryan-119](https://avatars.discourse-cdn.com/v4/letter/r/9de053/32.png) [@Ryan-119](https://community.cartalk.com/u/Ryan-119)\ **Post date:** [July 19, 2020, 10:30pm UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/7 "2020-07-19T22:30:55Z")
Hi, I have 109,000 miles on this car. It only makes the noise occasionally. Has no codes shown and I seen a video making a similar sound to this and the video owner commenting saying it was the brake actuator. I’m wondering if that’s what I should be worried about though. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [July 20, 2020, 3:17am UTC](https://community.cartalk.com/t/electronic-sound-when-braking-and-when-shifting-into-reverse-drive/167560/8 "2020-07-20T03:17:02Z")
If the brake booster pump cycles on/off frequently without cause there may be a leak in the booster/accumulator assembly. To identify the source of the noise you will need to show someone what you are listening to. There was a safety recall issued in 2013 to inspect/replace the brake booster pump assembly w/accumulator, if your vehicle has been to a dealer in the last 7 years this most likely has been completed. There was a customer support program (warranty extension) to cover the brake booster pump assembly w/accumulator issued last year however it expires after 10 years from the date of first use or 150,000 miles.