Hey fellow Redditors,

I need some advice regarding my 2004 Mercedes-Benz E320. A few months ago, the check engine light came on, indicating an issue with the secondary air pump. I took it to a mechanic, and they replaced the pump for me. However, here's where the problem persists - the pump wouldn't turn off.

To temporarily resolve this issue, I had to manually pull the relay connected to the secondary air pump. But now, the check engine light is indicating a problem with both the relay and the pump itself. I'm at a loss for what my next steps should be.

Has anyone else experienced a similar issue with their Mercedes-Benz or any other car? If so, I would greatly appreciate any advice or suggestions on how to resolve this problem. Is there a way to reset or troubleshoot the system without having to constantly disconnect the relay?

I'm open to any ideas or recommendations you may have. Thanks in advance for your help!

[Car Specs: 2004 Mercedes-Benz E320]