Mac Pro 2009 SMC Error. Please help!

Hi there, It's the first time I post here, any help would be apreciated.
I have a Mac Pro Early 2009 and since a few days all fans turn at full speed right after the startup chime. I've done SMC and PRAM reset several times with no success. I started AHT and it doesen't even start and throw back the following error: 4SMC/1/1000000: SMC (hope I wrote it right). I could download a copy of ASD and after the test there where several errors: all fan test failed and the sensor tests failed all (voltage and temp) that are located on the processor board (voltage 0 and temp 128c, all the same). SMC 2x2 also failed: SMC PID sensor has tripped. I've cleaned everything inside, reconnected all cables and took out all the RAM boards, left only one of four and suddenly it worked fine, ASD passed also all the tests... After two or three restarts the same issue started again and could not been solved by any try. I think the proccesor board is faulty but don't know if there's any solution.
Thanks for your support.

When the fans are quiet all sensors and fans work correctly and pass all tests. Still looking for solutions to avoid buying a new Processor board

Thanks for the link, but as I mentioned, all fans and sensor blow at full
and read 128c. Today after a couple of smc reset computer won't even start. After chime it Don't go further the grey screen with the Apple logo. Also I can't start ASD, it says starting leds and there it stays.... I'm getting out of ideas!

Yes, as soon as it boots, on all sensors on processor board... I've tested all connections and they're all right.

The ASD test for the Memory passed without errors. Tomorrow I will try the modules another time, have no other memory modules.

Today I finally brought the MP to an Apple Service Center. No warranty anymore...Argh! Hope it won't be to expensive. Thanks to all

Hi to all!
At the Service Center they told that they don't know exactly where the problem is !?!? They think that it is probably the backplane board. They told me that with these problems they usually change the two logic boards and the graphic card, and still so, they say it's like Lottery! What would you do? Change these components or go for something new? Any advice would be apreciated...

Hi! Thanks for quick reply.
I could flash my MP from 4.1 to 5.1 and downgrade without problems. The Dimm slots at inspection look fine, but I can do a more exhaustive inspection. Do you when I flash the MP the SMC firmware is upgraded to? If this is so, the SMC should be fine then... The battery looks good to me but I can try with another one and I should buy another RAM module.

Yes, it's driving me crazy! No leds light on on the MB. Only onr red led flashes when I plug in the power chord...

Is it possible to have a faulty Ram module, or all the four, with a passed ASD memory test and no Memory diagnostic leds on on the processor board?

So, finally I took Mysterium MP from the Apple Service, paid 88CHF for nothing (thank you Letec!) and went home, bought a new Backplane Board Battery and suddenly IT WORKS!!!!!! I can believe it!!!! Hope the problem is still gone today. Thank you all for your support!!!

So, more news, my MP is doing the same, again
I've tried anything, disconnect sensors, change battery, change RAM, disconnect all hardware (processors, RAM, graphic card, HDD) and still the same...
Mi question is, why after replacing the battery everything worked fine for a day? Is there anything that can work and not work? I think a faulty chip wont do this.
Next step, change logic boards? Any suggestions?
Thanks to all

I've tried to start MP without Battery, still the same problem... I will search for another Apple Service...

Finally, after more research looking at the errors ASD throwed back, I'm going to buy a new processor board from macparts. Hope this will solve the issue. Keep posting about it...