Secondary Air Pump - First Steps?
 

Probably asked a million times, so a thread link would work.

Here's the question:

2002 ML320

140k

check engine light/code : secondary air pump

swapped in a good, used air pump

inspected contacts and vac lines - all good

relay is good

cold engine - air pump is functioning and quiet

warm engine - pump stops running as it should

AFTER 5 MINUTE IDLING AT WARM ENGINE TEMP - throws the same code, light comes back on

What do I check next?

thnx

There is more to the system than pump and relay------if you have DAS there are questions to be asked of the system to further help define the real problem------see someone with a system

quick, straight answer

thanks

I’m getting the same code, I reset and can drive 10-20 miles before it comes on again. I’m thinking of buying an advanced code reader to diagnose as suggested. Any updates on what you have discovered?

No updates from me.

Waiting for my independent tech to do a comprehensive scan.

Might be this coming week.

Will update.

Any update on this ?

Did your issue get resolved? What was found?

what code ?