Secondary Air Pump - Replaced and still a problem
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Joined: Jul 2022
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C300 (2007)
Secondary Air Pump - Replaced and still a problem
HI,
I have a 2007 C300, first registered in Japan. Now in UK. I recently had an engine warning light appear. After taking it to the local garage I was told it was a failed Secondary Air Pump. I've since replaced it with a Bosch pump purchased online. I also purchased an iCartune V3 scanner. I cleared the fault log and all appeared well. I did have misgivings though because the old pump ran perfectly well when connected to a battery on the bench. Subsequently the warning light has appeared again, and their are two faults reported by the scanner - 'Low Air Pressure Bank 1' and the same for Bank 2. When the car was then in for MOT the garage identified a hose that had been gnawed into and sealed it up. The warning light has again come on. It seems unlikely that it is either of the valves or the pressure sensors (wherever they are) as the fault is always on both banks (V6). I did try activating the pump using the scanner - engine module - air pump, but it reported a communication failure. I don't know whether that is correct anyway or because there is a fault with the SAM (I hope not).
I'd be grateful for your thoughts and suggestions.
Regards
Peter
I have a 2007 C300, first registered in Japan. Now in UK. I recently had an engine warning light appear. After taking it to the local garage I was told it was a failed Secondary Air Pump. I've since replaced it with a Bosch pump purchased online. I also purchased an iCartune V3 scanner. I cleared the fault log and all appeared well. I did have misgivings though because the old pump ran perfectly well when connected to a battery on the bench. Subsequently the warning light has appeared again, and their are two faults reported by the scanner - 'Low Air Pressure Bank 1' and the same for Bank 2. When the car was then in for MOT the garage identified a hose that had been gnawed into and sealed it up. The warning light has again come on. It seems unlikely that it is either of the valves or the pressure sensors (wherever they are) as the fault is always on both banks (V6). I did try activating the pump using the scanner - engine module - air pump, but it reported a communication failure. I don't know whether that is correct anyway or because there is a fault with the SAM (I hope not).
I'd be grateful for your thoughts and suggestions.
Regards
Peter
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Joined: Apr 2015
Posts: 1,739
Likes: 120
From: London ON Canada
2012 C300 4Matic Sport Sedan
does the pump come on now? did they change the relay too? I'm on pump number 3 lol every 2 years i need to change it. i just go with the cheap $100 one now...its defiantly the upper and lower check valves that fail from carbon build up. i rebuilt mine and opened them up again they work find just the amount of carbon in them causes the pumps to **** the bed fast.
