Skip the auto shop - Our mechanics make house calls

Q: My Mercedes 2009 CLS 550 will crank but wont start

asked by on

My car started hard cranking 2 weeks ago after sitting in the garage for a week the next week it would not start at all checked the battery and fuses everything looks good

A: First, try using an alternate key. If it st...

First, try using an alternate key. If it starts easily with a different key, then the original key needs to be reprogrammed. If the problem persists with either key, then it could be the ignition switch or possible a fuel pump. If you would like help, have a qualified technician, like one from YourMechanic, diagnose the starting issue and guide with a repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Any DIY service manuals available? 2007 Mercedes S550

Hello - except for the Mercedes factory Service Manual/DVDs, the usual sources of quality aftermarket service manuals (i.e. Bentley) are bare on this one. Haynes/Chiltons don't yet cover anything this new either, certainly not for S-class models. Your best bet...

Q: Car wont start and the battery is great.

Hi there. Check the throttle position sensor on the throttle body and see if the sensor is working properly. The sensor is common to fail and cause the engine to not restart. I recommend replacing the throttle position sensor and...

Q: Car worked fine last night. Key won't turn in ignition this morning. Black looking liquid on key when taken out. Chimes sometimes.

Hello and thank you for contacting YourMechanic. There is a rubbery stick substance that is inside the ignition switch to protect the key as it is inserted. What seems to happen is the ignition switch got hot and melted the...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...