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2011 Mercedes S550 4matic P0109 code

  • draymond.green
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3 years 8 months ago #54270 by draymond.green
2011 Mercedes S550 4matic P0109 code was created by draymond.green
2011 Mercedes S550 4matic Lost communication with fuel pump control module P0109. I have became a professional parts changer ... I have bought a new fuel pump a new transfer evap canister check my relays all are good car cranks but won't start unless I put starter fluid in it then it starts straight up can someone please help me

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3 years 6 months ago #55344 by draymond.green
Replied by draymond.green on topic 2011 Mercedes S550 4matic P0109 code
Mr.Danner where are you its been almost 2 months youre the only person in the U.S that can help me i really would like to just bring my car to you please contact me. Thank you

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  • juergen.scholl
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3 years 6 months ago #55363 by juergen.scholl
Replied by juergen.scholl on topic 2011 Mercedes S550 4matic P0109 code
P0109 refers to a problem with the MAP sensor circuit, not so much to a communication problem....please verify.

Does/did the code return after changing the mentioned parts? Does the car keep running on its own after starting on external fuel?

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3 years 6 months ago #55364 by draymond.green
Replied by draymond.green on topic 2011 Mercedes S550 4matic P0109 code
Im sorry that code is U0109 an after ive bought new relays fuel transfer, fuel pump, had someone ck the wiring leading to the fuel pump an they were good all o can think of is the fuel pump control module it self but whats troubling is that I drove the car in the driveway shut it off an took the battery cable off bc the fuel pump was still running an now cranks but wont start only with starter fluid

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3 years 6 months ago #55366 by juergen.scholl
Replied by juergen.scholl on topic 2011 Mercedes S550 4matic P0109 code
I suppose the car will not keep running without external fuel and also that the fault code comes back immediately.....


Get the corresponding wiring diagram. Then check the powers and grounds and the communication lines of the fuel pump module. Report your findings.

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3 years 6 months ago #55367 by draymond.green
Replied by draymond.green on topic 2011 Mercedes S550 4matic P0109 code
Ok sounds good bv the transfer an fuel pump isnt getting any power at all

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