How To Clean The Battery Cooling Fan in A 2004-2009 Toyota Prius
Toyota Prius Battery Fan Cleaning
Why Clean The Battery Fan?
The battery cooling fan does its job hidden away behind the interior trim panels in the rear cargo space of the Prius. Toyota doesn't require or suggest cleaning this fan as a part of a regular maintenance schedule and most people won't ever need to. However, if you regularly carry furry friends in the back seat, you might want to do so every 60,000 miles or sooner. The battery fan intake vent in the rear-right of the Prius can suck in loose hair and debris, clogging the fins inside the blower fan that feeds cabin air into the battery pack to keep it cool.
If allowed to accumulate over time, eventually the fan can be completely clogged with fur and dirt, preventing the fan from doing its job of keeping the battery cool. This can cause error codes related to the battery pack overheating, reduced performance as the car's multiple ECU's (Electronic Control Units) limit the usage of the battery for driving or for regenerative braking and it can also lead to premature failure of the high voltage battery pack due to bieng subjected to extreme temperatures.
Picture Guide to Accessing Prius Battery Fan
Tools Needed To Get To The Battery Cooling Fan In A Prius
In order to remove the interior pieces and components in the way of the cooling fan, you will at least need:
- 1 x 10 mm socket
- 1 x 12 mm socket
- 1 x pair of good hands
I also recommend an upholstery pin removal tool that slides under the head of the push pin and allows you to pop it out much more easily than trying to pull on the material around it.
Upholstery Clip Removal Tool
Step By Step Directions To Remove The Battery Cooling Fan
1. Remove the rear back set cushion, it is held in place by two steel loops, one on each side and remove easily by lifting up with a steady pull.
2. Remove the bolt holding on the fan intake cover using a 12 mm socket.
3. Fold the seats down.
4. Remove hatch area carpet/mat and spare tire cover and cargo tray in the rear.
5. Remove the recessed bolt near the right rear seat belt using a 10 mm socket and extension and then remove the 10 mm bolt at the very rear of the vehicle on the right rear trim panel.
6. Remove the bolt and luggage tie down hook with a 10 mm socket.
7. Remove the bolts and luggage tie down hooks on the left and right rear on top of the battery pack.
8. Lift up and flip back the carpet pad cover over the battery pack.
9. Remove upholstery pin holding right rear trim panel on cooling exhaust duct.
10. Remove rear hatch trim piece covering the hatch locking mechanism (see photo) by gripping with both hands and lifting out.
11. Pop out both upholstery pins holding right rear trim panel (see photo).
12. Remove right rear trim panel.
13. Gently pull on the intake duct near the push pin holding it to the right side of the vehicle.
14. Remove push pin holding other end of intake duct to battery cooling fan (highly recommended to use an upholstery pin removal tool).
15. Remove intake duct.
16. Remove all three 10 mm bolts holding cooling fan on.
17. Remove the fan control plug by squeezing the clips on the side opposite of where the plug is mounted to and pushing them through (see photo).
18. Remove battery cooling fan power plug by squeezing the tab and gently pulling it out of the socket.
Re-installation is the reverse of removal.
Cleaning The Cooling Fan
If the fan is has hair or lint in it, try using a vacuum cleaner with a crevice tool to suck it out. For finer, stickier grime that won't vacuum off easily, use an old toothbrush or pipe cleaner to loosen and then vacuum it out.
When re-assembling, make sure you get the power plug for the fan reconnected before bolting everything back in or else your Prius will throw a diagnostic trouble code relating to the battery cooling fan not working (well duh) and you'll also have the master warning triangle lit up on the dash. This won't harm your Prius, its just letting you know something isn't right. The code can be cleared by disconnected the negative terminal on the 12 volt battery in the rear for a few seconds and reconnecting. Keep in mind that if you need to do this, you'll lose any radio presets as well as mileage driven and average mpg information and will have to re-initialize the auto roll down feature on the driver window by holding the control button down until the window is fully down and then holding it up until the window is all the way up before the auto feature will work again.