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rpmdiag, Tech and Instructor
Category: Mercedes
Satisfied Customers: 7762
Experience:  Since 1975
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I have a mercedes s600. it will not start. my certified

Customer Question

I have a mercedes s600. it will not start. my certified mercedes mechanic cant find out (he has had it over 3 weeks now). There is a new front battery ans new back battery everything will turn on but when you press the start button (or use the key fob) nothing happens. He put a new starter, but still didnt start. Originally went in the shop because it wouldnt start unless it was jumped. He put the new back battery and front battery in, test drove it, parked it and then when i went to pick it up it wouldnt start. I do know it needs a ignition coil voltage regulator (relates to error codes p300,301,302,303,304,305,306) but my mechanic says that is should still start....He has said he just doesnt know all diagnostics check out..any suggestion on what he might look at? or for?
Submitted: 1 year ago.
Category: Mercedes
Expert:  rpmdiag replied 1 year ago.

Hi, I’m Ron and I can help you.
I have been in the auto repair business with my own shops since 1975 and also teach automotive repair. I am confident we can resolve your problem together. Please understand that I don't know your skill level. In most cases when you have a problem with the way the vehicle performs, specialized tooling is required to acquire computer data/information or engine testing results. We didn’t build these complicated vehicles; we just diagnose and fix them. Also understand that I can't see, smell, hear, or touch the vehicle either, so it may take a few replies to get to satisfactory results. I am also going to direct you with the fastest, easiest and most common things to check first. Please be patient and permit me to do what I do best.
I also try to give all of the information you may need, expecting a “positive rating” in return. I will also continue assisting you after you have rated me, if necessary. If there is any reason I cannot get a positive rating, please let me know why “in advance”, so I can go another direction for you. I am sorry you’re having this problem; I’ll help you through it.

Those are all misfire codes, have him check for a good strong spark at the plugs and check the ignition module/coils. If they are all showing a misfire, it won't start. Check CRANK sensor too.

Thanks, Ron