# 03 Prius Hybrid System Warning Light On **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** prius, toyota\ **Created:** [May 6, 2018, 2:07pm UTC](https://community.cartalk.com/t/03-prius-hybrid-system-warning-light-on/116863 "2018-05-06T14:07:25Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![kevsy](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/kevsy/32/11596_2.png) [@kevsy](https://community.cartalk.com/u/kevsy)\ **Post date:** [May 6, 2018, 2:07pm UTC](https://community.cartalk.com/t/03-prius-hybrid-system-warning-light-on/116863/1 "2018-05-06T14:07:25Z")
Yesterday, just as I got home my 2003 Prius’ hybrid system warning light came on. This has happened a few times in 15 years but has always been associated with moisture getting into the rear battery vent. In the past, if I turned the car off and on a couple times or waited for it to dry out 15-20 minutes, the light went off and the car drove normally. This time, the weather was hot (95 F.) and dry. I tried turning it on and off several times but the light stayed on. Has anybody out there had a similar experience, or suggestions? Thanks in advance! ---
**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:** [May 6, 2018, 4:13pm UTC](https://community.cartalk.com/t/03-prius-hybrid-system-warning-light-on/116863/2 "2018-05-06T16:13:32Z")
You might post this on a Prius site, like priuschat. May be time to have it scanned for codes by a shop familiar with the Prius. ---
**Author:** ![kevsy](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/kevsy/32/11596_2.png) [@kevsy](https://community.cartalk.com/u/kevsy)\ **Post date:** [May 25, 2018, 2:07pm UTC](https://community.cartalk.com/t/03-prius-hybrid-system-warning-light-on/116863/3 "2018-05-25T14:07:19Z")
Thanks for the advice. After eliminating simple causes, like fuses or a sticky throttle body, I took it to my friends at Japanese Car Service, and they retrieved the error code for inverter pump failure. The good news is, this was not a very expensive repair. And I now know that this repair shop is absolutely competent to work on hybrids, including battery replacement later on, if I need it. A win/win situation! ---
**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:** [May 25, 2018, 2:18pm UTC](https://community.cartalk.com/t/03-prius-hybrid-system-warning-light-on/116863/4 "2018-05-25T14:18:13Z")
Good news! Thanks for letting us know.