Engine will not crank over sometimes.... Not starter?

ian-g

New Member
Joined
Aug 9, 2018
Messages
9
Reaction score
1
Your Mercedes
2009 cls 350 cdi
Hi just re joined as could not reset password.. 09 cls 350 cdi. Occasionally when I turn the key to the start position it does not crank over or make any noise or click, but here is the strange thing... If I return the key to IGN ON and try again it still will NOT turn over, I can try countless times, but if I bring the key right back to off and try it will start as normal. This makes me think its not the starter motor or solenoid. Any thoughts?
 

John Laidlaw

Senior Member
Joined
Nov 15, 2013
Messages
26,373
Reaction score
9,163
Location
Wirral
Your Mercedes
Land Rover Discovery 4
Checked battery and connections?
 

mioba

Senior Member
Joined
Feb 19, 2006
Messages
7,898
Reaction score
4,656
Location
Nottingham and Köln
Your Mercedes
W124/E200, W220/S320CDI, W205/C200, W251/R350CDI 4Matic
Basics, get a voltmeter and check battery without load and with load to see if the battery is fit and the charging circuit works.
Make sure connections are clean and tight and no oxidation.
Beyond that could be a starter relay, faulty ing switch. May be worth and Indy for star.
Cheers
 
OP
ian-g

ian-g

New Member
Joined
Aug 9, 2018
Messages
9
Reaction score
1
Your Mercedes
2009 cls 350 cdi
  • Thread Starter
  • Thread starter
  • #4
if i take the key back to off it starts fine so not battery....but if i take the key back to ignition on then it doesn't so i suspect its an electronic fault.
 

LostKiwi

Senior Member
Joined
Aug 25, 2006
Messages
31,324
Reaction score
21,574
Location
Midlands / Charente-Maritime
Your Mercedes
'93 500SL-32, '01 W210 Estate E240 (RIP), 02 R230 SL500, 04 Smart Roadster Coupe, 11 R350CDi
Is this not the protection mechanism? Once you've tried to start the car it won't allow another attempt without the key being turned off. Both the 210 andv230 do this (so does the 129 for that matter).
 
OP
ian-g

ian-g

New Member
Joined
Aug 9, 2018
Messages
9
Reaction score
1
Your Mercedes
2009 cls 350 cdi
  • Thread Starter
  • Thread starter
  • #7
Ah thank you... that explains why I have to take it back to off.. What's your thought of it occasionally not turning over?
 

LostKiwi

Senior Member
Joined
Aug 25, 2006
Messages
31,324
Reaction score
21,574
Location
Midlands / Charente-Maritime
Your Mercedes
'93 500SL-32, '01 W210 Estate E240 (RIP), 02 R230 SL500, 04 Smart Roadster Coupe, 11 R350CDi
Ah thank you... that explains why I have to take it back to off.. What's your thought of it occasionally not turning over?
My guess would be a bad starter relay
 

Steve@Avantgarde

Forum Supporter
Authorised Forum Supporter
Joined
Dec 8, 2009
Messages
7,314
Reaction score
1,955
Location
Bristol/Somerset
Website
www.avantgarde-automotive.co.uk
Your Mercedes
E300 Coupe AMG Line PP/NE, SLR McLaren Roadster, SL55 & C32AMG
I wouldn't guess at anything.

You need to check the drive authorisation path of the EIS. Doing lots of EIS switches at the moment for this kind of failure. The new EIS units still turn even with a foreign key unlike the old ones that used to lock.
 
OP
ian-g

ian-g

New Member
Joined
Aug 9, 2018
Messages
9
Reaction score
1
Your Mercedes
2009 cls 350 cdi
  • Thread Starter
  • Thread starter
  • #10
I wouldn't guess at anything.

You need to check the drive authorisation path of the EIS. Doing lots of EIS switches at the moment for this kind of failure. The new EIS units still turn even with a foreign key unlike the old ones that used to lock.
Thanks how do I go about checking it?
I presume this needs some equipment or a specialist?
 

Steve@Avantgarde

Forum Supporter
Authorised Forum Supporter
Joined
Dec 8, 2009
Messages
7,314
Reaction score
1,955
Location
Bristol/Somerset
Website
www.avantgarde-automotive.co.uk
Your Mercedes
E300 Coupe AMG Line PP/NE, SLR McLaren Roadster, SL55 & C32AMG
Thanks how do I go about checking it?
I presume this needs some equipment or a specialist?

An Indie or the dealer is the only route I would say, unless you find someone who has access to STAR
 
OP
ian-g

ian-g

New Member
Joined
Aug 9, 2018
Messages
9
Reaction score
1
Your Mercedes
2009 cls 350 cdi
  • Thread Starter
  • Thread starter
  • #12
Thank you all for the help... Much appreciated.
 

You lost your key ? Or maybe you need a spare! Your vehicle imobilliser does not respond anymore? WE CAN FIX THEM ALL !! Mobile ! Save Time and Increase Profits With us !
Top Bottom