DTC 27AF (P1411) - Secondary Air Pump - HELP!

My recently acquired 2009 E90 M3 came with a CEL. No biggie, or so I thought. The code is 27AF - Secondary Air Pump.

First I replaced the pump. CEL on 2nd cold start.

Then I replaced the suction hose, which includes the air flow meter that detects the pump's operation. CEL on 2nd cold start.



Throughout this I've been running the ESS tune that the car came with. I am going to flash back to the stock 240E software tonight, but I don't think this is going to fix the problem.

The only thread I found was this one: http://www.m3post.com/forums/showthread.php?t=951276

I thoroughly checked all of the connections. All of the hoses are properly seated.

Maybe it's the battery, as some suggested in that thread.

Any insight would be greatly appreciated!

http://www.m3post.com/forums/showthread.php?t=928325

Id recommend saving this link

Did you replace the hose with a new one or used? Did you inspect it prior to install? Because other than the sensor a crack in the tube will cause CEL too

Yes, I found that thread in my searches. It doesn't contain anything helpful for solving my issue, unfortunately.

Edited first post

http://www.m3post.com/forums/showpost.php?p=15510080&postcount=51

Did you also see the "action in service"?

EJT86 wrote

Did you replace the hose with a new one or used? Did you inspect it prior to install? Because other than the sensor a crack in the tube will cause CEL too

New hose and no cracks. Pump is new too. I couldn't see the output hose well enough to look for cracks. Since the sensor is upstream of the pump, it should only throw a CEL if there were a crack upstream of the sensor.

EJT86 wrote

Did you also see the "action in service"?

The pump definitely runs. It's loud and the idle sounds like junk until the pump turns off. I haven't pulled the relay to jump it because I'm sure it's running.

It looks step 4 is cut off. I wonder what else it recommends...

schickane wrote

New hose and no cracks. Pump is new too. I couldn't see the output hose well enough to look for cracks. Since the sensor is upstream of the pump, it should only throw a CEL if there were a crack upstream of the sensor.

Did you clear the code after you replaced the pump and hose? I just had a cel and it was the hose sensor I replaced it and cleared the code and was good to go. Carly app and dongle will do that and also check your battery voltage

EJT86 wrote

Did you clear the code after you replaced the pump and hose? I just had a cel and it was the hose sensor I replaced it and cleared the code and was good to go. Carly app and dongle will do that and also check your battery voltage

Yes, I cleared it with the ESS software and cable. It came back after the 2nd cold start, about 10-15 seconds after starting the car.

I will check battery voltage tonight as well. Is there a voltage below which people start to have issues?

schickane wrote

Yes, I cleared it with the ESS software and cable. It came back after the 2nd cold start, about 10-15 seconds after starting the car.

I will check battery voltage tonight as well. Is there a voltage below which people start to have issues?

I'm not sure if there's a voltage limit that's specifically related to the secondary air pump. But this past winter there was a couple times where my car sat for about 10days straight and I got a low voltage warning. Things like comfort access didn't work until it was recharged. Mines at about 15v I think it was at 13ish when that happened. I checked it to monitor if it would recharge fully cuz it took a few days of 1 hr driving to get rid of the warning. I believe the life of our batteries is about 6 years so if you've got a '09 it might be time

Thanks for the info! I'll report back.

Without disconnecting anything, the battery was reading 12.28 V. I suspected this was due to the trunk light and the other electronics that turned on when I unlocked the car. I disconnected the negative terminal and the battery read 12.58 V. It's an OEM battery, but I didn't see any dates printed on the top. I suppose it could be original.

Next I cleared the codes. I did not start the car.

I then proceeded to flash the car back to the OEM 240E map. The car went berserk during the flash process, with all sorts of warnings about the transmission and ABS popping up. Scared me a bit. The process finished successfully.

I started the car, and the CEL was on and stayed on. Weird. I let the secondary air pump run its cycle, then shut the car off.

Then I cleared the codes again. After clearing the codes, I realized I had to set the date and time, so I did that before starting the car. Just after I finished doing this, I got the Low Battery Voltage warning! I immediately started the car and took it for a drive around town.

Weird stuff. I plan to replace the battery tomorrow with a Duralast Platinum H8-AGM. It has 900 CCA and 90 Ah just like the OEM battery. My Carly dongle arrives tomorrow so I'll be able to register the battery properly.

Fingers crossed. I forgot to try jumping the SAI relay, I'll do that tomorrow.

I put in a new battery last night. The one that came out was stamped with a 2011 build date, so it was definitely a smart move to replace it.

I noticed that the CTEK connector has 3 LEDs on it: red, orange, and green. I had only seen it blink red on the old battery. It blinks green on the new battery, so I have high hopes that this fixes my issue.

I will report back!

schickane wrote

I put in a new battery last night. The one that came out was stamped with a 2011 build date, so it was definitely a smart move to replace it.

I noticed that the CTEK connector has 3 LEDs on it: red, orange, and green. I had only seen it blink red on the old battery. It blinks green on the new battery, so I have high hopes that this fixes my issue.

I will report back!

I'll probably need a new battery soon too

its possible you may have bad valves that the air pump sends air to. I have a pair of used ones for cheap if you like.

schickane did you ever resolve this ?

EJT86 wrote

Did you clear the code after you replaced the pump and hose? I just had a cel and it was the hose sensor I replaced it and cleared the code and was good to go. Carly app and dongle will do that and also check your battery voltage

where is the hose sensor ?

jeremyuhh wrote

schickane did you ever resolve this ?

Same issue here too, also curious if anyone resolved this