Air pump is not turning on - 1998 V70 T5

maxtegroom · Post by **maxtegroom** » 05 Apr 2011, 06:58

I have a 1998 V70 T5 B5234 i just replaced my whole PVC system even the canister under the IM and now i have a P0410* i believe and my air pump is not turning on i have power to the fuse the fuse is good, i have power to the relay in the "kidney" shaped fuse box, and when i jump the two large relay terminals the pump turns on.. but the pump will not turn on when i start the car up and eventually the CEL will come on again... now i have a confusing alldata wiring diagram and it looks like the the Cooling fan relay is the air pump relay which in located above the cooling fans under a little cover is that the cooling fan relay or another air pump relay... please any added information will be a huge help thank you in advance...

Post by **Jack Rock** » 05 Apr 2011, 07:14

It's not uncommon for the air pump itself to crap out. The Volvo ones are a bit pricey but if your handy check this out...

https://www.matthewsvolvosite.com/2009/1 ... ial-volvo/

Also, you would be best to check out the wiring diagrams hosted on this site under repair database tab. I forget which relay it is but when you find it just jumper the two larger pins, if the air pump doesn't run then it's bad.

Post by **cn90** » 05 Apr 2011, 07:34

Actually the above link is for a used VW motor, not a good idea b/c you don't know how long it will last.

I wrote a DIY for Air Pump (usually the bearing goes bad):
https://www.matthewsvolvosite.com/forums ... =1&t=28683

Another option is to use a "Hobby Lobby Toy Graupner Speed 900 BB motor" ($60) but you have to modify things a bit.
I posted the info on BMW forum, read thread #35:
http://www.bimmerfest.com/forums/showth ... 816&page=2

PS: Of course you have the option of buying a new Pierburg Air Pump, but it is pricey.
PN 9179271 ---> $360!!!

Usually the Air Valve goes bad causing Pump failure. Air Valve PN is 9125623, about $100-120 ---> Change this first.

cxf · Post by **cxf** » 05 Apr 2011, 08:19

Hi maxtegroom,
I did the vw air pump install into my daughter's S70 a couple of years ago. It is a very easy procedure and the pump is the same internally so you just need to interchange a few housing parts between the 2 airpump units and you are good to go. Way cheaper than buying the Volvo unit. Just be sure to drill a couple of small holes into the bottom of the housing to allow any moisture to drain. I also was able to return function to the mushroom shaped valve between the engine and firewall by spraying carb / choke cleaner in and letting it soak in for a few days. These get caked up over time like an egr does and allow moisture to find its way to the pump.

good luck, Dan

Post by **cn90** » 05 Apr 2011, 08:53

Drilling the holes in the air pump is a myth in this forum.
I did that and regretted!
Then I plug it with silicone caulk.

In 100% of the time, the water condensation comes from bad Air Valve, which should be changed every 100K miles or so.

maxtegroom · Post by **maxtegroom** » 05 Apr 2011, 09:05

the air pump works just fine i can jump the relay and the pump will come on right away the pump is about a year old i also changed the whole air pump system, and i switched the relays with the main relay and the car started so it is not the relay or fuse. for some reason the pump it not being comanded on when is supposed to?? anybody have this problem?? what about the relays someone tell me that there is only 1 relay on my 98 v70 and its the one in the fuse box not the "cooling fan" relays above the rediator...

Post by **cn90** » 05 Apr 2011, 09:17

Then check the Solenoid Valve (for Air Pump) PN 1270389.

Post by **JRL** » 05 Apr 2011, 09:21

I have a good used SAS air pump
You will need to buy a new check valve but you can have the pump for $125 plus shipping

maxtegroom · Post by **maxtegroom** » 05 Apr 2011, 11:00

THE AIR PUMP WORKS JUST FINE!!! i can jump the relay and the pump will come right on.. can a broken check valve have anything to do with the pump not coming on. on the valve i feel it opening and closing and the vacuum hose has vacuum so i know the valve should be good i just cant understand why my wires have correct voltage but the pump is not coming on by itself..

Post by **dcarlson12** » 05 Apr 2011, 13:25

Attached is a section from VADIS. Perhaps this will help????
Hope you will let us know when you get things working...