# Speed message 107mph after changing speed sensor **URL:** \ **Category:** Power/Fuel\ **Tags:** chevrolet, impala\ **Created:** [July 24, 2020, 4:10am UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787 "2020-07-24T04:10:14Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Twinn213](https://avatars.discourse-cdn.com/v4/letter/t/7feea3/32.png) [@Twinn213](https://community.cartalk.com/u/Twinn213)\ **Post date:** [July 24, 2020, 4:10am UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787/1 "2020-07-24T04:10:14Z")
I just put a speed sensor on my car because the speed has slowed,my speedometer is going crazy with a speed107mph message.Did the diagnostic and it stated needed that sensor .Now it’s on there nothing has changed.Helppp. I have no lights on the dash. ---
**Author:** ![COROLLAGUY1](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/corollaguy1/32/7575_2.png) [@COROLLAGUY1](https://community.cartalk.com/u/COROLLAGUY1)\ **Post date:** [July 24, 2020, 11:58am UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787/2 "2020-07-24T11:58:18Z")
Maybe the speedometer is kaput. ---
**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 24, 2020, 12:25pm UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787/3 "2020-07-24T12:25:34Z")
So you own an Impala. You changed a speed sensor and now you have some kind of problem. That is all I can get from your post so I can’t help unless you tell me more. What year, mileage, and transmission? What diagnostic? Read codes? What exact code did you read? Now explain more fully the problem you are seeing. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [July 24, 2020, 1:39pm UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787/4 "2020-07-24T13:39:59Z")
Instrument clusters go bad, Wiring goes bad, Wire connectors go bad, Control modules go bad. But Sensors very seldom go bad. ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [July 24, 2020, 2:23pm UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787/5 "2020-07-24T14:23:19Z")
If you can’t provide all the information that @Mustangman asked for, you should have a shop diagnose the problem and fix it. ---
**Author:** ![Twinn213](https://avatars.discourse-cdn.com/v4/letter/t/7feea3/32.png) [@Twinn213](https://community.cartalk.com/u/Twinn213)\ **Post date:** [July 24, 2020, 6:10pm UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787/6 "2020-07-24T18:10:27Z")
I have a 2007 chevy impala. 150000 miles. 3.5l,I took it to a mechanic because it is reading speed107mph,the speedometer is going crazy ,the acceleration has stopped at 25 miles per hour. I can still drive the car but it’s slow and it stalls.I had a diagnostic done and the code read p0720 updated speed sensor.I then had it changed the same day but am still having the same problems.I have no check engine lights . ---
**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 24, 2020, 6:23pm UTC](https://community.cartalk.com/t/speed-message-107mph-after-changing-speed-sensor/167787/7 "2020-07-24T18:23:20Z")
So the speed sensor was bad and now it isn’t since it no longer throws a code. Clearly you have another problem. The wonky dash sounds like a failing BCM…Body control module. It needs to go to a good repair shop to diagnose if the BCM is bad and if anything else is contributing.