Hello everyone im having issue with starting my ml320. after a series of events and repairs my truck was back up and running then now its not even starting. When i turn key into both positions all lights on dash board come on and light up , little red led light blinks to show key recognition but will not crank or start just dead. Battery is good, Starter seems ok, i am able to start it by jumping starter relay fuse with jump wire. but for some reason cannot get it to start without jump wiring the starter relay fuse. i dont know what could possibly be the problem ?? im thinking either crank position sensor , bad fuse box or bad fuse somewhere or starter( although car starts with wire jump) or something with ignition or loose wire somewhere. im just stuck scartching my head on what it could be im thinking about purchasing a scanner to read the system although the check engine light is not on.any ideas anyone or thing i should try or suggestion on a affordable scanner that might help me find out whats going on??

 

Did you at anytime attempt to jumpstart with key in the ignition?

I doubt it's the CPS. You woul still be able to crank, but not start.
Possibly, Post #2

As for a scanner, You can test your ECU with one of these - invalulable tool -

 

yes i believe i did jumpstart with key in ignition i think. was that a bad thing?

 

YES, a bad thing.
Do you have another FOB key or valet key?

post#2,
https://mbworld.org/forums/m-class-w...mediatley.html

 

i do not have another fob but i had a valet key made i have to go pick up a stealership but valet key is different from key tumbler in ignition valet its just to open doors but im sure i can finagle a way to put current blade key onto new valet transponder key. unless there is another solution u guys have.

 

No,the valet key DOES operate the vehicle just like the other fob keys. It does contain an RFID chip for the DAS in the handle, just like the other keys.
Who told you this?

 

i do think that the current key is recognized tho because i see the little led light next to radio blink each time position 1 and 2

 

no its not that it wont operate it im saying i changed the key tumbler out to another tumbler with a different key blade that was added to my key fob. the new valet key wont go into the tumbler because its from the original key cut for the vin of the car

 

Follow post #4 here for testing

 

Please show me where in your 1st post you said you changed the key tumbler.

 

sorry didn't mention that

 

that link doesn't work

 

oh yea didnt mention either the key fob does not work, that why i ordered valet key to open and lock doors

 

link corrected.

 

ok so the blinks when in position 2, and engine cranks when i jump the wire from starter relay spot 30 to 87, also i changed out to new battery. i also just tried to switch one of the relays from the rear windshield wiper to k12 which is circuit 15 to see if it would start no luck. so im thinking either aam/ecm or ignition switch??

 

Any ideas anyone??

 

ok guys just did a test with the car key ecu card suggested earlier and noticed the led light on the dash next to radio blinks on and off when in key position 1 and when it is in key position 2 it does not blink at all this happens also on the card.so from the card details it say the key is not programmed to the vehicle if the light is blinking so i think i found my problem.any suggestions or ideas on how to deal with this?

 

the reason i always saw the one blink when i put the key in is because i always just turned the key to position 2 is that normal?