is there a fan in there...I was driving home no music and in the quieness of my Pri...I hear this sound....any one else familiar with this sound?
The vent at the back seat is an -intake- for the battery cooling fan. Which is why you want the air temp in the car not too high. The fan is about 1 1/2 ft down the "tube". The hybrid system battery cooling fan exhausts at the front of the 12V battery into the side of the car and out underneath it. If that makes any sense. You can see it if you remove the hatch floor and the cover over the 12V battery.
I've monitored the fan speed on ours via ScanGauge, seen it as high as 4 (on a scale of 6 I think). My hearing's not that great, but at level 4 I still couldn't hear it. Have you had the car for some time, driven with radio off, but only hearing it now? Not to be an alarmist, but it MIGHT indicate a struggling battery. Or (better) a clogging fan. The latter is much easier to deal with. It's an inlet at that grill, btw. If you transport pets it can accelerate fan clogging. Re battery health, how many miles on the odometer?
I only recently bought a Scanguage for my gen 2. Do you know can o check fan speed on the SG for my car? If yes, where?
not sure re 2nd gen. Someone was asking here lately, believe something was possible, code was posted.
Summer heat will cause this...endless summer in CA? OK I hear ya.... We always say use A/C to keep car cool so battery cooling is helped. We have had very few Gen3 batt failures to date, so we shall see future when it comes,but seems like Toyota knows how to manage the battery pretty well.
We used AC for first time in a while today. Car had been driven earlier in the day, so battery a little hot right from the outset. Ambient temp was 27C, climbed to 29C by our destination, about 10 km distant. Battery temp at outset was 37C (Scangauge reading middle battery sensor). Ran AC at a comfortable level, 10 km and ~20 min's later battery temp was: 37C
I posted some data wayback about fan speed and corresponding battery temp, vehicle speed, etc. While I didn't post any data related to A/C state, I do recall that the fan always blows at least at level 1 if the A/C is on in the vehicle. Here's a link to the post Traction battery fan. re-posted below: ---------------------------------------------------------- Originally Posted 9-20-12 ---------------------------------------------------------- Old thread, but I've been monitoring HV Battery Fan Speed and wanted to throw up some of my charts to add to the conversation. It appears that the Fan comes on as soon as the Traction Battery Temperature reaches 97F (according to the #2 PID for battery temp). As others have said, if the battery temp is above 97 (or 100 as another poster suggested), the fan is on, if the temp is below 97, it's off. Always. Figuring out exactly what conditions cause the fan to enter modes 1-6 is much more complicated. It depends on ambient air temperature at a minimum, but could involve other factors as well. My data suggests that vehicle speed is not a factor. The first chart below shows MAX, MIN and AVG Traction Battery Temp (#2) by fan speeds. As you can see, 97 degrees is the on/off point. The second chart shows battery vs cabin temp - there is much less to be learned from that. FANSpeed by bendertj, on Flickr Next chart shows fan speed vs vehicle speed. Again, not much of a pattern there. FANSpeedCarSpeed by bendertj, on Flickr This final chart shows how often the fan is operating in each mode. This data was collected over the past month while ambient air temperatures ranged from 50F to 95F. LVLpie by bendertj, on Flickr
