SAI question

[Tailwind]

I'm getting ready to tear into troubleshooting my P0410/P1411 codes and had some questions for the experts.
When you activate the pump via Durametric, does it also activate the changeover valve?
If you do the above with the engine stopped, can you feel air coming out of the tailpipe?
My experience with this CEL is it did not trigger after the first 90 second run, and I did sit at a light for a couple minutes; then the next time I was stopped and the SAI ran for a second time, I got the CEL. I read the SAI runs a second time to "test the integrity of the system". What is this and why didn't I get a CEL the first time I was sitting after the first SAI? This happens every time I take the car out.

tia

[911monty]

If a malfunction is detected during the 1st trip, the first trip DTC is stored in the ECM memory. The MIL light will not light up (two trip detection logic) If the same malfunction is not detected in the second trip, the 1st trip DTC is cleared from ECM memory. If the same malfunction is detected in the 2nd trip, both the 1st trip DTC and 2nd trip DTC are stored in the ECM memory and the MIL lights up.

In other words, the DTC is stored in the ECM memory and the MIL lights up when the same malfunction occurs in two consecutive completed trips.

When the MIL is set freeze frame data is also stored to help in troubleshooting.

Good Luck

[Tailwind]

Originally Posted by 911monty

If a malfunction is detected during the 1st trip, the first trip DTC is stored in the ECM memory. The MIL light will not light up (two trip detection logic) If the same malfunction is not detected in the second trip, the 1st trip DTC is cleared from ECM memory. If the same malfunction is detected in the 2nd trip, both the 1st trip DTC and 2nd trip DTC are stored in the ECM memory and the MIL lights up.

In other words, the DTC is stored in the ECM memory and the MIL lights up when the same malfunction occurs in two consecutive completed trips.

When the MIL is set freeze frame data is also stored to help in troubleshooting.

Good Luck

Thanks so much. It's clear now!

[Tailwind]

So I removed the Alternator and air pump. This helps access wise. I then removed the right intake manifold. I saw that the check valve input (vacuum side) was not connected to anything. (more on that). I removed all of the SAI components and hooked up everything on the bench and vacuum tested with the HF brake bleeder pump. Everything held up. I blew through the shut-off valve and it was closed tight. I applied 12V to the change-over valve with my bench supply and the change-over valve opened with a resounding clunk, and air moved freely. Initially I couldn't find where vacuum line to the check valve was but found it. I think I might have disturbed it when I cleaned the throttle body a month ago, and it slipped off.




Took it out for an errand and no CEL so far