# Cruise disengages and speedometer flutters **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [June 14, 2008, 10:15pm UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336 "2008-06-14T22:15:03Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![ginab1157](https://avatars.discourse-cdn.com/v4/letter/g/e9c0ed/32.png) [@ginab1157](https://community.cartalk.com/u/ginab1157)\ **Post date:** [June 14, 2008, 10:15pm UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/1 "2008-06-14T22:15:03Z")
I have a 2002 Kia Optima, 6 cylinder, with 157K miles. The cruise disengages and when that happens, the speedometer flutters back and forth from 0 to 80. The engine speed doesn’t waver, it just slows because my foot isn’t on the gas. It doesn’t disengage every time I use it, but when it does occur, it will happen several times in a row. I have replaced the cruise control unit, but that didn’t solve the problem. I have also noticed that it may be happening at the point of shifting up to the next gear, but I’m not sure that the two events are connected. I’d appreciate any insight you can give me. Thank you. ---
**Author:** ![SteveF](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/stevef/32/2_2.png) [@SteveF](https://community.cartalk.com/u/SteveF)\ **Post date:** [June 15, 2008, 2:15am UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/2 "2008-06-15T02:15:28Z")
It is unfortunate that you already replaced the cruse control unit, which probably was working perfectly. A car will automatically drop out of cruise control if the computer thinks its speed has dropped too far. Since both the computer and speedometer can only judge speed from the input of the VSS (vehicle speed sensor), my guess is that you have a flaky VSS. ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [June 15, 2008, 2:24am UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/3 "2008-06-15T02:24:53Z")
I agree. The vehicle speed sensor is likely to to be the problem. Too bad you already spent the money for a new cruise control unit. Was that your decision, or a mechanic’s? ---
**Author:** ![Thalon](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Thalon](https://community.cartalk.com/u/Thalon)\ **Post date:** [June 15, 2008, 4:08am UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/4 "2008-06-15T04:08:01Z")
Does this car have an automatic transmission? ---
**Author:** ![Thalon](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Thalon](https://community.cartalk.com/u/Thalon)\ **Post date:** [June 15, 2008, 4:12am UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/5 "2008-06-15T04:12:14Z")
Check to see if this car has a flex drive cable from the transmission to the speedometer. If it does a worn cable can cause the speedometer to jump around. Expecially if the cable is dry. May just need to lube it or replace it… ---
**Author:** ![ginab1157](https://avatars.discourse-cdn.com/v4/letter/g/e9c0ed/32.png) [@ginab1157](https://community.cartalk.com/u/ginab1157)\ **Post date:** [June 16, 2008, 12:01pm UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/6 "2008-06-16T12:01:47Z")
The mechanic’s. ---
**Author:** ![ginab1157](https://avatars.discourse-cdn.com/v4/letter/g/e9c0ed/32.png) [@ginab1157](https://community.cartalk.com/u/ginab1157)\ **Post date:** [June 16, 2008, 12:03pm UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/7 "2008-06-16T12:03:01Z")
Yes. It can also be shifted manually. ---
**Author:** ![cappy208](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cappy208/32/31_2.png) [@cappy208](https://community.cartalk.com/u/cappy208)\ **Post date:** [June 16, 2008, 12:19pm UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/8 "2008-06-16T12:19:10Z")
the question was does this car have an automatic transmission. it has either a manual (stick shift) or an automatic. ---
**Author:** ![SteveF](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/stevef/32/2_2.png) [@SteveF](https://community.cartalk.com/u/SteveF)\ **Post date:** [June 16, 2008, 2:17pm UTC](https://community.cartalk.com/t/cruise-disengages-and-speedometer-flutters/15336/9 "2008-06-16T14:17:05Z")
I don’t think the type of transmission is relevant. Manual, automatic, or even CVT, the symptoms all point to a malfunctioning VSS.