Hello,
I have a 2009 ML350 4Matic with an odd starting issue. I went out to the vehicle last week and click, click, click... dead battery. Took to local MB dealer and replaced battery. Drove the car Monday through Friday early morning to work, and later at night home.
Over the weekend, I started the car and drove to multiple locations without issue. I left the car in a sunny parking lot for 30 min. While coming out of the grocery store, I pressed the button on the FOB to open the trunk. The trunk opened about 6 inches then froze in place. Then, when putting the key in the ignition to start the car, the car would crank but not start. After multiple attempts, the car cranked and ran for 1 second before dying. No codes or error lights on dash (including the suspected EIS failure - “key does not belong in vehicle”). After waiting 5-10 minutes, the car started as it should and I drove home, but with limited functionality of both key FOBs. I had the car towed to the local dealer and of course, now it is starting and running fine. Any ideas as to what could be causing this? I don’t want to throw an $1100 EIS module at it without being sure.

 

Try replacing all key fob batteries.

There should be an auxiliary battery, in addition to the main vehicle battery. Was the auxiliary battery replaced? It is located in the same general space as the main battery, under the passenger seat.

 

Chassis, the key fob batteries are obviously working as they opened the door/s and the tailgate.

The only function of the Auxiliary Battery is to supply voltage to the Servo Module so that the shifter can be placed in "Neutral" so it may towed, if the main battery is dead.

 

Have you visually checked to see that you received a new battery? All dealers are thieves.

If you are getting that message in the Inst. Cluster, there will be a corresponding code stored in EIS Control Module.

Additionally, you probably own a cheap code reader that will only read engine codes and nothing else. You must own your own scanner.

 

All,
Thanks for the ideas. The batteries in both key fobs are new. The main battery is a new MB battery. There are no lights or error codes present.
The rear hatch was replaced with a used hatch 2 years ago due to minor cosmetic damage. Am I being paranoid to think that there could be an issue with the rear hatch wiring harness thats causing the system to ‘short out’ when opening the trunk?
The vehicle has been issue free until now.

 

What system is shorting out?

 

Good question... immobilizer possibly?

 

Liftgate latch defective? Not communicating electrically that it is closed and locked?

 

Liftgate latch is new as of 6 months ago

 

Do you own your own scanner? If not get this one and check for codes in the DAS (Drive Authorization System]

 

To everyone who contributed to this post, thank you for your help and ideas. This was the culrpit:

Checking the amps/fuses lead me to this. Replaced and the problem is solved. Controlled all power going to rear fuse box. Car now runs 100%

Hope this helps someone in the future!

 

Where is that fuse located?

 

Congratulations, well done. Is that a one hundred amp fuse?

 

Nice work man! Don’t know where that is located though. I’ll take a look at mine.