c55 Secondary air pump help?
Thread Starter
Junior Member
Joined: Jun 2016
Posts: 50
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From: St. Louis MO
07 E63
c55 Secondary air pump help?
I have an 05 C55 amg with 127k miles. Two months ago the secondary air pump was replaced. Last week engine light came on and autozone code reader said P0410 (secondary air pump). Took it to local dealer and there computer came up with a fault code p2003 not P0410. After spending $840 to replace an electrical module (they call front SAM), they then tell me the pump is bad too. They want $1500 to replace the pump. The pump is right on top and I wanted to know if I would mess up anything with the computer/module if I replaced it myself? Does it need to be OEM? I saw a new one on ebay for $150. Also, who ever replaced the air pump hardwired it rather than using a connector. Not sure why someone would cut off a electrical connector just to hardwire. Any help would be greatly appreciated.
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E55
Does the pump run? At that mileage it could be just a cracked or soft vacuum supply line for the switchover valve. Was the relay replaced when the pump was replaced? The relay is usually the cause for the pump burning out.
Thread Starter
Junior Member
Joined: Jun 2016
Posts: 50
Likes: 2
From: St. Louis MO
07 E63
air pump
After replacing SAM, the dealer checked power going to the pump and it's good. So they say the pump is shot. I don't think the relay was replaced when they changed the pump. It's still the purple relay with Mercedes logo, I would assume an aftermarket relay wouldn't look like that. They used a Bosch pump, so it's not a cheap part.
Sounds like you guys think it could have been the relay that caused the pump to go out (since they didn't change it with the pump). Any thoughts on where I could get a connector, in case the hardwire was a possible cause. Would any of you use the ebay pump for $150 or go with another Bosch?
Sounds like you guys think it could have been the relay that caused the pump to go out (since they didn't change it with the pump). Any thoughts on where I could get a connector, in case the hardwire was a possible cause. Would any of you use the ebay pump for $150 or go with another Bosch?
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E55
If they are telling you it needs another pump then why dont they parts warranty it? What happens is the old relay sticks and causes the pump to run continuously until it burns out. Why did they replace the Sam? The Sam Comes with all the new relays and fuses in it so not sure why they didn't just do the relay and fuse.
Thread Starter
Junior Member
Joined: Jun 2016
Posts: 50
Likes: 2
From: St. Louis MO
07 E63
This local dealer didn't replace the pump. I live in MO now, and the pump was replaced at a small shop in CO on 9/30. I guess that shop didn't replace the relay at that time. Since they just replaced SAM, my engine light isn't on now but I'm sure it will come back since the pump isn't working. So, I shouldn't have to buy a new relay since the SAM was replaced?
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MBWorld Fanatic!
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E55
This local dealer didn't replace the pump. I live in MO now, and the pump was replaced at a small shop in CO on 9/30. I guess that shop didn't replace the relay at that time. Since they just replaced SAM, my engine light isn't on now but I'm sure it will come back since the pump isn't working. So, I shouldn't have to buy a new relay since the SAM was replaced?
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Joined: Oct 2013
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From: Dark Side, Canada
'06 Mercedes C55
I have 95k miles in my C55 and one day the secondary air pump didn't shut down. It heated up and sounded like it burnt up when it finally turned off. I thought I had to replace it, but it turns out it still works. After this incident I went home and unplugged the fuse and relay, looked through everything and it seems to be working ok now. Here is a video showing how to replace the pump. It only supposed to come on for around 30 seconds to pump fresh air into the exhaust when the engine is cold, it is for emission reasons. I'm hoping to reflash the ECU next summer, but I have to check if this eliminates the secondary air pump kicking in as well. If it does, I will be removing this stupid pump completely; it's an eyesore in the engine bay.
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C55 AMG
Hi Guys, mine appears to run all the time when the car is running, it shuts down with engine shut down though.
Is this the relay problem or does the relay problem run the pump after engine shutdown?
Any other ideas?
Thanks
Is this the relay problem or does the relay problem run the pump after engine shutdown?
Any other ideas?
Thanks
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Joined: Nov 2014
Posts: 1,139
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E55
MBWorld Fanatic!
Joined: Nov 2014
Posts: 1,139
Likes: 77
E55
Junior Member
Joined: Oct 2013
Posts: 53
Likes: 1
From: Dark Side, Canada
'06 Mercedes C55
Hi Guys, mine appears to run all the time when the car is running, it shuts down with engine shut down though.
Is this the relay problem or does the relay problem run the pump after engine shutdown?
Any other ideas?
Thanks
Is this the relay problem or does the relay problem run the pump after engine shutdown?
Any other ideas?
Thanks
Junior Member
Joined: Oct 2016
Posts: 64
Likes: 14
C55 AMG
That still wont isolate the problem though will it?
The relay must be triggered by likely an ECU output which will be told to turn the pump on via some inputs, if i pull the relay the pump will stop, thats a given, but replacing the relay with a new unit will be pointless if the relay is still being driven on by the ECU constantly.
What tells the ECU to turn on the SAP relay?
Temp input?
Ill likely just get a relay anyway and replace to see if it goes away as they are cheap enough. but if its not the relay, where to from there?
The relay must be triggered by likely an ECU output which will be told to turn the pump on via some inputs, if i pull the relay the pump will stop, thats a given, but replacing the relay with a new unit will be pointless if the relay is still being driven on by the ECU constantly.
What tells the ECU to turn on the SAP relay?
Temp input?
Ill likely just get a relay anyway and replace to see if it goes away as they are cheap enough. but if its not the relay, where to from there?
MBWorld Fanatic!
Joined: Nov 2014
Posts: 1,139
Likes: 77
E55
That still wont isolate the problem though will it?
The relay must be triggered by likely an ECU output which will be told to turn the pump on via some inputs, if i pull the relay the pump will stop, thats a given, but replacing the relay with a new unit will be pointless if the relay is still being driven on by the ECU constantly.
What tells the ECU to turn on the SAP relay?
Temp input?
Ill likely just get a relay anyway and replace to see if it goes away as they are cheap enough. but if its not the relay, where to from there?
The relay must be triggered by likely an ECU output which will be told to turn the pump on via some inputs, if i pull the relay the pump will stop, thats a given, but replacing the relay with a new unit will be pointless if the relay is still being driven on by the ECU constantly.
What tells the ECU to turn on the SAP relay?
Temp input?
Ill likely just get a relay anyway and replace to see if it goes away as they are cheap enough. but if its not the relay, where to from there?
MBWorld Fanatic!
Joined: Nov 2014
Posts: 1,139
Likes: 77
E55
Power steering? Guide pulley? I'd buy an automotive stethoscope and pin point it.
