TO1993S4

Hi Guys, firstly it is pretty cold here right now, but can you tell me if your secondary air pump comes on with each cold start please?

I just noticed if my car is not started for a couple of days that during initial start up the secondary air pump does not seem to come on, which I believe it is supposed to with each cold start.

I scanned for fault codes but there are none. I did output tests using VAG COM and the pump works. The weird thing is if I use the car and then start it the very next morning, everything works as it is supposed to - secondary pump runs during cold start for about a minute and then shuts down.

Does anyone have a diagram showing how the secondary air system works on our cars? During cold start does the ECM get the signal to trigger the the secondary air system from the coolant temperature sensor?

Thanks for any help.

hahnmgh63

Mine seems to for about 1 minute, then idles down the same time the pump kicks off.

Yellow RS 6

Everytime I start my car when it's cold, there's a humming sound on the passenger's side for 30-60 seconds, then it goes away. I wasn't too worried since it is consistent, I just didn't know what it was.

LIRS6

^^^ what he said ^^^

hahnmgh63

An electric air pump which injects during cold start to keep emmissions down.