07 s550 won`t start when cold, fuel pump doesn`t get power
Thread Starter
Junior Member
Joined: Jan 2012
Posts: 20
Likes: 1
07 mercedes s550
07 s550 won`t start when cold, fuel pump doesn`t get power
car wont start when the engine is cold or even after 10minutes break,
It cranks but dosent start up.I changed cps, and now thinking it could be a fuel pump. I checked and there is no power coming to the fuel pump when I try to start and I heard that is because of computer which see that something is wrong with the pump so it doesn`t send the power, is it true or it may be something diferent? And I know for sure that car doesn`t start because engine doesn`t get fuel.but if it starts its only after trying for 5-30minutes then it drives just perfect with out any problem.
When engine is hot there is no problem with starting..... Help please
It cranks but dosent start up.I changed cps, and now thinking it could be a fuel pump. I checked and there is no power coming to the fuel pump when I try to start and I heard that is because of computer which see that something is wrong with the pump so it doesn`t send the power, is it true or it may be something diferent? And I know for sure that car doesn`t start because engine doesn`t get fuel.but if it starts its only after trying for 5-30minutes then it drives just perfect with out any problem.
When engine is hot there is no problem with starting..... Help please
MBWorld Fanatic!
Joined: Dec 2008
Posts: 2,396
Likes: 38
From: Bay Area, CA
2007 SL55 AMG
have you tested running direct power the the fuel pump and cranking it? Check all fuses on the rear SAM. I've seen this problem before, and it ended up being the rear SAM that was defective. The ignition sends power to the rear SAM, which then sends power to the fuel pump.
Thread Starter
Junior Member
Joined: Jan 2012
Posts: 20
Likes: 1
07 mercedes s550
have you tested running direct power the the fuel pump and cranking it? Check all fuses on the rear SAM. I've seen this problem before, and it ended up being the rear SAM that was defective. The ignition sends power to the rear SAM, which then sends power to the fuel pump.
....I`m writing this just in case somebody gonna have similar problem.
