Wont Start

[TeesML500]

Hi,
Advice needed. I have a 2002 ML 500. It has about 40K miles on it. My kids have been using it and we are now down to one key. The transmitter does not work. I have to use the key to open the doors. When I get in I turn the key and all of the accessories work. The radio and lights are all on. However there is no crank when I fully turn the key. It is just dead. Nothing. A day or two later I will try again and it will work fine. Im confused. The other night the car was dead again. I pushed it a few feet to move it closer to the curb. When I tried again it worked. Do you think it could be the key or the battery?? Please let me know. thanks.

[azinn]

First thing I would do is remove the battery cables and clean the contacts. My .02

[TeesML500]

I will try that. I spoke with MB service dept on the phone. They said it could be the battery or the crankshaft position sensor. Is there such a thing???

[azinn]

Originally Posted by TeesML500

I will try that. I spoke with MB service dept on the phone. They said it could be the battery or the crankshaft position sensor. Is there such a thing???

Yes there is a CPS (crankshaft position sensor) and it does fail. That would be the second thing I would check out. Usually when the CPS fails the engine will crank but not start and happens when the engine is hot. My .02

[TeesML500]

OK I changed the battery. Bought a new one. After cleaning the cables well and installing it. It starter for one second and shut down. It did that two or three times. After that it was nothing again. Although I did hear a winding or spooling sound coming from what sounded like the front of the engine compartment on the drivers side. ANy idea where to look next??? Thanks.

[mbdoc]

If the ML is from 2002-2005?? then the key is the most likely problem.

Most send an anti-theft signal to the transponder ring around the key tumbler.

Take your proof of ownership to your local dealer to order new KEY.

[TeesML500]

Thank you for the advice Doc. I will try that this week.