I've got a 98 s70t5 115k. check engine light has come on. autozone read codes for me and it's p0410. what is the procedure to properly check the system and diagnose? Thanks

 

Either the air pump or valve is bad.
Do you hear like a hair dryer noise in the morning after first starting the car?

 

Today in the morning I listened . . . .absolutely no such sound inside the cabin or under the hood either. What's next?

 

Air pump is bad.

 

Do I need a new one($$$) or is there a way to save(fix) the one i've got? 2. where can I get a guide how to do the job(properly the first time) my chilton & haynes manuals don't cover it . . .Thanks

 

You will have to buy a new one.
Find the sensor it sticks out the front of the booster between the booster and the engine.
Look on the booster there is a metal ring that locks it in. Use a hook tool to pull the ring and release the sensor.
But first pump the brake pedal till it gets hard.

 

I've just heard from a friendthatthe air pump on his 98 s70 went bad too,he replaced it, and the replacement went bad as well, a short while later.
Can it be that this trouble we're having with the air pumps is being caused by something else? Combination valve perhaps?
( I'ts just that I'd like to be 100%sure everything else is o.k. before I put in such an expensive piece $350-$450) Thanks

 

Never replace the air pump without changing the bad check valve that caused the pump to fail or the new pump will also fail. Check out this thread from Swedespeed.

http://forums.swedespeed.com/zerothread?id=89794

 

I have a 98 V70R and have this code. Check engine light came on after a long sit under some snow. I have the hairdryer sound when I start the car - does that mean this is a valve issue?

 

You can start chasing it or just bypass it.

 

Look for RSPI's video on how to bypass it. Works like a charm and solved all my issues with the P0410.