Secondary air pump issue...

poppydoodlesdad

Active Member
Feb 6, 2012
27
0
Hello,

I have a bit of a problem with the secondary air pump not switching off when the ignition is turned off and then running the battery flat. At first I could hear something running and thought it was the fan but having had a look it is definitely the secondary air pump. It has on occasion gone off and on once the ignition is off.
My understanding is that the secondary air system helps heat up the catalytic converter on a cold start, but I have seen elsewhere that some people remove this completely, so I wonder what its value is ultimately?
But this raises a few questions:

a) what could be causing the pump to run on after the ignition is off? Especially what might cause it to go off and on intermittently? (a sensor?)

b) once the catalytic converter is at working temperature shouldn't the pump switch off? Does it run continuously?

c) if this system can be removed entirely would it be OK to "unplug" the pump as a temporary measure just to prevent running the battery down? Could this be done by removing the appropriate fuse and/or power connector to the pump?

Thanks in advance...
 
Last edited:

300bhpdaily

Active Member
May 26, 2020
1,245
565
Hi what engine is it for? If you unplug the pump you will get a EML I did this years ago on my 1.8t as the pump was screaming and had a new one on the way so unplugged it and afew days later the light came on for the pump. It should only come on for afew seconds on cold starts. Maybe 20s max.
 

poppydoodlesdad

Active Member
Feb 6, 2012
27
0
Hi what engine is it for? If you unplug the pump you will get a EML I did this years ago on my 1.8t as the pump was screaming and had a new one on the way so unplugged it and afew days later the light came on for the pump. It should only come on for afew seconds on cold starts. Maybe 20s max.

Many thanks.
It's a 1.6 petrol. The pump seems OK, just won't switch off (well it does sometimes). I need to use the car really but it is not convenient to get it seen to right now. I only want to ensure it doesn't run the battery down between stops.
No ideas about what might be causing it to run on?
Thanks
 
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