Sometimes Wont crank over W221 350d 2011

[BarndooBen]

2011 S Class 350 blue eff. Sometimes doesnt crank over . Take Key out , back in , lock , unlock . After a time of two it starts. When it wont start dash lights read Run flat unavailable and car skid symbol on . Then it starts and is perfect . Could be again today or a few days later. Got all the readouts but no light is shed on problem . Be grateful for any help. Thanks lads

 

[BarndooBen]

Now i have to disconnect and replace Neg Battery terminal most times or it wont start , Any Ideas guys ? Its been in Lookers for 6 weeks .

 

[Petrol Pete]

Do no codes come up when the car is scanned ?

 

[W1ghty]

You can fill your boots on this huge thread on the other MB forum about a non starting S class.

W221 S350 not starting (doesn’t even try) after service.

It’s all your fault [emoji23] Sent from my iPhone using Tapatalk Usually is, I’m married

forums.mercedesclub.org.uk

 

[BarndooBen]

Do no codes come up when the car is scanned ?

No mate nothing its in Lookers still . Even when it wont start no codes present

 

[DSM10000]

No mate nothing its in Lookers still . Even when it wont start no codes present

Did you get the same fault if you try both keys?

The electronic ignition switch can cause non start/ non crank problems, another possibility is the crankshaft position sensor and ?camshaft sensor faults but I would have thought these would have shown fault codes.

 

[BarndooBen]

Did you get the same fault if you try both keys?

The electronic ignition switch can cause non start/ non crank problems, another possibility is the crankshaft position sensor and ?camshaft sensor faults but I would have thought these would have shown fault codes.

Yes mate tried both keys ,it happens with both. Its not showing faults at Merc dealers .They are at a loss too.!2 months is a long time to live with this fault but recently Its Neg Battery lead of and back on It starts straight away.

 

[BarndooBen]

Do no codes come up when the car is scanned ?

None Pete

 

[W1ghty]

Yes mate tried both keys ,it happens with both. Its not showing faults at Merc dealers .They are at a loss too.!2 months is a long time to live with this fault but recently Its Neg Battery lead of and back on It starts straight away.

Have you had a chance to look over that thread ?

 

[BarndooBen]

Its taken me all afternoon me heads hurting. I wont be chucking all that money at it. I love the car but 7 times out of 10 it will not crank. Run-flat and ESP Messages on dash. When it starts its perfect.
If it doesn't start its neg terminal off and on then it goes and messages disappear. Tell me you know a man

 

[W1ghty]

Its taken me all afternoon me heads hurting. I wont be chucking all that money at it. I love the car but 7 times out of 10 it will not crank. Run-flat and ESP Messages on dash. When it starts its perfect.
If it doesn't start its neg terminal off and on then it goes and messages disappear. Tell me you know a man

I was sort of thinking that if you skip to the very end , the problem was the Terminal 87 Relay . I doubt it costs much so might be worth starting with what the OP thought was the solution ??

 

[BarndooBen]

I was sort of thinking that if you skip to the very end , the problem was the Terminal 87 Relay . I doubt it costs much so might be worth starting with what the OP thought was the solution ??

I'm gonna get it back on Monday and try that mate ,and I thank you for your diligence in trying to help me .I really hope this works. Ksebs has responded too, he says i should try this first too. I'll keep you informed if it works .Cheers Tez

 

[W1ghty]

I'm gonna get it back on Monday and try that mate ,and I thank you for your diligence in trying to help me .I really hope this works. Ksebs has responded too, he says i should try this first too. I'll keep you informed if it works .Cheers Tez

Good luck buddy , sounds like a nightmare !

 

[BarndooBen]

W1ghty and DSM1000 AND PETROL PETE You have my undying thanks .The relay cured the starting problem ,but chucked a couple fault messages on Diags. Ran like a pig. Swirl Flap doofer replaced .Sweet as a nut .Leaking O ring covered the unit in oil shorted it out and knackered the Relay.I got it home last night and my Audio just stopped working, but the car runs great.F'in chuffed Thanks lads .

 

[BarndooBen]

And especially ,thanks to ksebs