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Thank you so so much for the detailed reply. Really appreciate it. I will first start with replacing the relay and the 40A fuse to see if that helps if not i will replace the secondary pump which from the videos in you tube does not seems like too difficult
few questions if you know the answers thanks again!!
is there any tricks to check the existing relay or the fuse to confirm they are good or bad ?
is there any easy indication that pump is the problem after the relay is replaced?
does this pump runs all the time when the car is running or only runs when car starts and or in idle state etc.?
location of the secondary air injection pump relay and fuse for 2003 ML350
Thanks. When the check engine light first started to coming out months ago, with the scanner that I have it only shows this P0410 secondary air injection System code (attached)
does the more advanced scanners shows what piece is causing the generic P0410 code ?
Last edited by Papillon; Jul 20, 2022 at 03:01 PM.
thanks for the PDF with all the codes in . this is really good information to have !
i searched through the pdf and looked for P0410 and i see 2 hits ::
P2023 Relay for air pump (P0410)
P2003 Malfunction of secondary air injection (P0410)
my cheap scanner only can show P0410 but does not show any internal code that isolates whether it is a relay or the pump - so i guess i will start with replacing the relay and if that does not fix replace the pump Does any fancy scanner actually shows P2023 or P2003 levels of details of an error code?
BTW the last picture that you send - it indicates the relay fro the secondary pump is on passenger side fuse box? is that easily accessible or i have to take off bunch of stuff to get to it. sorry i dont have ML at my this week so was not able to take a peek.
wanted to update that the P0410 code was not due to secondary air pump!. When i opened the engine cover (i know I should have done that months ago instead of sitting on it and asking questions in this forum) and started to take off the pump with an E10r revers torx (which btw also had to purchase just for this) i saw that the small hose connecting it pump was actually cleanly busted open!
So i replaced the hose with a $1.99 hose ( i found a 3.8mm one in AutoZone,, Mercedes spec was 4mm but thats fine), just needed a 1 ft length and damn all good!, Reset the code with my OBD scanner and the code never came back.
I however Needed to finish the drive cycle though before emission test which btw is another ordeal for ML350 ( i have different thread on that) .but at the end car passed emission and i am good for another 2 years!!
so both relay and secondary air pump was good the hose was the issue
see the picture of the busted 2 dollar hose! Dealer or other mechanic would have probably charged me for pump relay and new hose most likely ~ 1000 bucks or more plus stupid 200/hr of labor. i just had to spent 1.99 plus tx and times on the internet and in this forum which is awesome
BTW for reference if any one really needs to replace the pump or relay::
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
