# 2010 Toyota Prius fuse problem **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** fuses, prius, toyota\ **Created:** [April 16, 2018, 6:15pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784 "2018-04-16T18:15:11Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Joe09](https://avatars.discourse-cdn.com/v4/letter/j/e79b87/32.png) [@Joe09](https://community.cartalk.com/u/Joe09)\ **Post date:** [April 16, 2018, 6:15pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784/1 "2018-04-16T18:15:11Z")
My Check PCS Light came on for my 2010 Toyota Prius. I read somewhere that it could be the battery not providing enough voltage. I check with Multimeter and found a parasitic drain of about -2.0amps. When i pulled the ECU-B fuse, that went to nearly 0. Now I am stuck figuring out what that means or how to fix it. The car wont run without this fuse (not like I can just disable the radio and ignore). So how do I stop this drain? What is actually wrong? Isnt the ECU the main computer of the car? ---
**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:** [April 16, 2018, 7:23pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784/2 "2018-04-16T19:23:23Z")
You may have to monitor the draw for up to 30 minutes with the doors, trunk and hood closed to reach a normal value, there is likely nothing wrong as far as a battery draw. If the battery is weak/failing replace it before further testing. PCS is Pre-Collision System, a professional diagnostic scan tool will be needed to read the faults in that system. Is there any damage to the front of the car near the radar sensor? ---
**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:** [April 20, 2018, 2:26pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784/3 "2018-04-20T14:26:36Z")
I would agree: definitely eliminate the battery first as the cause of a warning light. When my wife’s 2006 battery failed a while ago, the transmission failure warning light came on. Once the battery was replaced, there were no more problems. ---
**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:** [April 20, 2018, 2:43pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784/4 "2018-04-20T14:43:14Z")
How old is the battery? ---
**Author:** ![Joe09](https://avatars.discourse-cdn.com/v4/letter/j/e79b87/32.png) [@Joe09](https://community.cartalk.com/u/Joe09)\ **Post date:** [April 20, 2018, 2:47pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784/5 "2018-04-20T14:47:51Z")
Battery was only 5 months old. I just had it replaced yesterday with Optima Yellow top. Same issue. I’ll put a multimeter on it and see if it is good, but highly unlikely that 2 batteries in a row are bad. Gotta be the car at this point. And I think I hear some sort of Arcing or Sparking coming from the back when I drive. maybe there is a wire with a crack causing some arcing and loss of power? ---
**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:** [April 20, 2018, 2:54pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784/6 "2018-04-20T14:54:11Z")
When it comes to electrical issues like this, I find an expert. You might try posting this on a Prius forum, maybe somebody there has had the exact same problem (Priuschat, for example). ---
**Author:** ![Joe09](https://avatars.discourse-cdn.com/v4/letter/j/e79b87/32.png) [@Joe09](https://community.cartalk.com/u/Joe09)\ **Post date:** [April 20, 2018, 3:11pm UTC](https://community.cartalk.com/t/2010-toyota-prius-fuse-problem/115784/7 "2018-04-20T15:11:24Z")
Agreed. Thanks for your advice. I’ll probably just take it to a mechanic/dealer at this point.