1997 850: throws DTC P0410 between 87-90 miles of drive Topic is solved

[Chuck W]

I did the SAS delete on the wife's '97 GLT. I cracked open the ECU and just added the diode there. Easy enough.

[RickHaleParker]

Should I just go ahead and service the valve -- hose connections for damage, repair, and replace gasket?

Unless you can hear the pump run continuously, it is the pump or the wiring.
Disconnect wiring harness, apply power directly to the pump, does it run?

[xHeart]

I am not seeing any electrical connector at the sas valve, what fails? Can it be soaked and cleaned off of carbon deposits, etc.

Meanwhile, found this by cn90 viewtopic.php?f=1&t=28683&start=20

[RickHaleParker]

I am not seeing any electrical connector at the sas valve,

Pump Pump Pump.

[erikv11]

Is the pump full of water? Does it turn on? Checking the air pump for water is the best diagnostic for a bad SAS valve.

I am not seeing any electrical connector at the sas valve, what fails? Can it be soaked and cleaned off of carbon deposits, etc.

Meanwhile, found this by cn90 viewtopic.php?f=1&t=28683&start=20

The SAS valve opens and closes by vacuum. The vacuum is provided via the SAS solenoid: signal from the ECU controls the SAS solenoid, electrical switching of the solenoid sends IM vacuum to the SAS valve which opens the SAS valve. When the signal from the ECU goes away the solenoid switches off the vacuum and the SAS closes. How they fail: An old SAS valve gets stuck open, this allows exhaust gases to constantly flow to the air pump, causing it to fill up with water. The SAS valve was redesigned at some point so the newer ones do not corrode so easily inside to not get stuck so much. I've never heard of cleaning one but that's possible.

You can blow/suck on the port nipple and see if the valve opens and closes properly. Sounds like you've had this car from new and not replaced the SAS valve so 99.9% chance it doesn't work right.

Rehabbing an air pump is a lot of fun for some, I suppose.

[xHeart]

For a quick check if pump is running, I'd unscrew the hose clamp and pull off the hose at the valve. Start the motor, air blows out of the hose, or not, at the valve then I have the answer, right?

[misha]

Nope!
You need to remove the hose from air filter housing...not from SAS valve.
If you remove it from sas valve you should feel a vacuum not air blow.
Sas system and pump is operated by ecu.
It should turn on on cold engine for just about few seconds.
The easiest way to test it is to apply 12v directly on it.

[erikv11]

I would apply 12v to it directly, you can run a wire down from the battery + pole. Just touch to it, it should spin right up. Or start the engine when cold and reach down put your hands on the pump - is it running?

Here's some good, basic troubleshooting tips see the post by "Drew" http://volvospeed.com/vs_forum/topic/40 ... -air-pump/

[xHeart]

Thanks!
There is no water in the pump, appears completely dry.
Do I connect battery + for 12V to blue wire connector? What about the back ground wire?

MVS_AirPump_0082.jpg (336.69 KiB) Viewed 1215 times

[erikv11]

Oh, dry pump that is good news but I am surprised! Starting to sound more like a vacuum leak problem but def test the pump while it's out.

Positive battery cable to the blue wire, black to a ground point on the engine. Should spin right up - be careful it may jerk a little from the torque as it spins up.

Any vacuum leak in the SAS system will set that code. The precision of 87-90 miles is a stumper, though.