Maciek Michalak

I woke up this morning on a cold day, started my car and the amazing check engine light was on. Code came up as p0411 secondary air injection. Can someone help me out, i dont know where to start

KyleB

year and model?

Maciek Michalak

2004 530i M54

KyleB

Your secondary emissions air pump is located on the right side of the engine bay towards the front of the car. Its purpose is to inject fresh air through the exhaust system during COLD operation in order to dilute the exhaust gasses and bring the catalytic converter and oxygen sensors online as quickly as possible. Once the engine warms up, the pump turns off.

If you are getting a fault code for it, it likely has stopped working (not uncommon). It affects absolutely nothing in terms of proper engine operation, driveability, safety, etc. You can either:

A. - ignore it
B. - replace it
C. - remove it completely and install an emulator from a place like Active Autowerke, Turner Motorsport, etc.

Good luck with the car.

Maciek Michalak

Thank you so much

Chicken Bone

Hi All. I have had this P0411 code as well, and cannot pass NC Emissions inspection. Sorry for the long post, but here are the actions I have taken:
1) Replaced Blown 50A fuse for SAI pump
2) Replaced bad relay (stuck open) for SAI pump.
3) Verified 12V at pump wiring harness.
4) Removed SAI pump (full of water/carbon) and tested (on bench) with external 12V (pump ran fine)
5) Drilled 1/16 inch hole in bottom of pump housing to drain water, sprayed WD40 in pump.
6) Allowed 2 days for pump to dry, retested then reinstalled.
7) Replaced Secondary Air Check Valve and gasket
8) Had check engine light (CEL) reset with Actron scanner
9) 3 days later CEL is back on.
10) Had code scanned at Advance Auto...still showing P0411 code with "(Pending)" also displayed.

Not sure what to try next. I think the pump is fine. Could a faulty Secondary Air flow sensor cause this code? I assume it's output partly controls the actuation of the SAI pump relay. Ugh.

Chicken Bone

To add to previous post; since I've heard that the SAI System really has no influence on the car's performance, I'm more interested in just passing the NC Inspection. I just had the CEL light reset and it's off. The local mechanic said for me to drive it 100 miles or so then bring it in for an inspection attempt. Does anyone know what condition must be present for the SAI pump to be commanded on? Cold engine, or cold outside air? If the SAI pump only comes on when the engine is cold, what if I were to drive it through a complete drive cycle, and never give the engine a chance to cool off? Would this put the car in a "readiness" state to pass inspection, even if there is still a faulty SAI system?

KyleB

I used to live in Virginia, so we had similar vehicle inspections. If I were you I would:

A. - give the guy $50 to pass the car
B. - buy an emulator from AA, Turner, etc

good luck with the car.

ncsugrad2006

Indeed--emulators are cheap and/or easy to build. Also not so legal.

Anyways--if yours is a 6 cylinder model, I know some come with an air flow sensor connected to the secondary air system. This could be failing and a generic code reader not pick up the code for it. What are you using to read codes?

That would be where I would start. Sounds like you have replaced everything else just about

Chicken Bone

Thanks KyleB and NCSU. I hope I'm wrong, but I thought the State somehow electronically tracks the readiness or emissions status through the Inspection Station's computer. I figured that's why they can't just choose to pass the car. I doubt my guy will go for the $50 incentive.

So far, all I know is Actron scanners were used to read the codes. Not sure which models. I see if it passes in a few minutes. I've driven 80 miles with 3 cold starts since it was reset. Still no CEL.

If it doesnt pass I'll replace or clean the Secondary MAF sensor and try to move forward.

Small world NCSUGrad2006. I went to EE Grad school for about a year there. Shouldve studied Automotive Engineering!