Hello to all Volvo lovers,
after reading, studying and learning from different threads I still need help, it's the code p0410. Had this problem for a while, but since it was not that crucial to have it fixed, I let it be ignored ( 3 to 4 years ) until now, the inspection time. I replaced the air pump, valve and the solenoid with oem parts.The pump was filled with water, the valve was " frozen" solid and the solenoid was stocked open. Now everything seems to work when being tested individually, the solenoid opens when the car starts cold and the vacuum opens the valve but the pump does not kick in, but it runs if I jump it. Exchanging relays proofs that they are o'k. It seems to me that something is preventing the signal to reach the relay, yet it seems to reach the solenoid when starting the engine cold. Need your help, please!

 

I guess you can tell it's my first time, screwed up the font size and forgot to list my car description,
'98, S70, 2.4 t5 non turbo, 160 000 miles
thanks in advance

 

Any other codes stored in the computer?
Also did you already clear the codes stored?

 

There was an issue with code P0172, I tried to clean maff and busted it, bought one on E'bay made it worse (same part #, but the car would run worse it would hesitate a lot) In the mean time, thanks this forum and you guys, found and fixed the vacuum line elbow under the fuel rail, but the code would always come back. Bought a new maff (oem), car runs great and that code was taken care of it seems.
Yes I clear all codes ( have my own reader ), but it takes a while to get the system ready again becouse of relatively short commuting ( 12 miles ).
Yesterday, after getting that code P0410 I ran all tests of all these componets as described in original post and wanted to clear it, the reader would say 2 codes storeed, but only would display one, P0410. After few etempts I gave up and cleared them all. I assumed that the second code (unknown) would be the result of my testing?
Thanks Tech.

 

have to assume it's a T5 turbo. You said NON turbo.

I generic code reader won't find all the codes. You need a Volvo Dealer or an indy to see if codes are still lurking.

For 410, I would think a study of all the vacuum lines, and air lines, specifically to the air pump and intake would be in order.

172 may be an O2 sensor or a MAF like Tech said, or simply a vacuum line.