http://bootmylaptop.com/ibm-lenovo-fan-error/
http://apttech.wordpress.com/2011/02/05/lenovo-t410-fan-error/
My 1 year old Lenovo T410 started to get an Fan error during booting. I wonder if this is caused by me recently using the laptop positioned in a holder at an angle, or possibly due to the computer failing to suspend because of firefox/flash using 100% or processor over night.
I was a bit upset about this error because I recently got around to setting up my linux debian squeeze system to the point were wireless networking works perfectly, and fixing a problem with screen brightness.
Some advice suggested trying to remove dust, pressing laptop in certain location, or replacing the fan.
Error occurs only on a fresh boot, seems worse if laptop has been in transit, or has been switched off for some time. Some of comments on the Lenovo discussion board reported a lot of failures on Monday in office situation, after users have taken laptops home during weekend.
After reading 9 pages of discussion, there is some advice to update the bios, the download is available from Lenovo support, Download. I applied this update from Windows 7, after fully charging the battery and with power connected and with no other programs running.
I haven’t received the error again after the BIOS update, but only had a few boots. Had the fan error warning last week once, and repeatedly yesterday (fortunately laptop eventually booted normally). Fan seems to sound same as usual and is pushing heat out from laptop, so I hope there is no hardware problem.
bainite 
Still had error again after bios update. Wondering if I get this error only when running from Battery.
Had the same thing yesterday. Tech support where I work replaced the fan today
I might be a distant cousin (James Peet, Plymouth, MN, USA)
Fan Error
I had the same issue with my laptop all i had to do was to clean fan it had a lot of dust in it after it was done laptop work fine
to clean the fan should I use an airfan or am I missing something?
I think a Hoover/Vaccum cleaner is a good option. I think that is what I did in the end.
I used canned air on a network switch while it was on and broke it before. So if you want to use canned air then make sure to not blow out any liquid air from it, and make sure to power off and remove battery.
Fan Error es un problema de Ventilacion de la maquina, es necesario limpiar el ventilador con limpia contactos dejarlo secar por almenos unos 3 minutos y volver a iniciar la maquina.
Now my laptop being very unstable and even hardly boots. I have to contact the suppliers. Probably best to contact them as soon as you start to have fan errors.
*sigh* great. One year old and dying already… You know this is a major issue if google autocompletes “fan error” as “fan error Lenovo t410” before any other computer/model out there.
A Lenovo field service technician revealed that he has a lot of calls about T410 fan errors and Lenovo should have done a factory recall on all T410s. Apparently, your fan has already fail or will fail soon.
The permanent fix is to have the CPU fan replaced while under warranty. The newer fans provide more coolant through its new structure thus, better lubrication for the fan to spin.
I was so disappointed my laptop wasn’t working…. Eventually today I rang up lenovo for to regarding the warranty support. They didn’t ask any questions after I said there was problem with the fan. Since my laptop was bought with 3 year warranty, they told me to send it to a local service centre so It is in the post now. Hopefully it will come back in working order (better?).
Last time I sent my laptop and it came back with new fan. I still had problems with the graphics card which was causing system to crash. The latest driver available for windows can recover when the graphcis card freezes but still results in loss of data from the programs you are using at the time. With just the new fan the graphics card was reaching very high temperatures, and crashing/ screen was freezing very often. Crashing could be caused easily by few minutes of use, or fairly reproducibly by minimising and maximising the windows. Even bios program for checking the hard disk would cause graphics card to freeze.
I contacted lenovo a second time and they have now replaced the motherboard of the laptop. It seems working OK again. Hope so.