manishjain24

I searched the forum for the pop-up (Remove Button, Insert Key) I came across numerous threads that have good data but none with the same issue I am encountering.

2016 E400 4Matic with 45K Miles.

This morning I was rushing for an appointment, I parked the vehicle, when I got out, I touched the door handle and thought I had locked the car.

An hour later, when I was returning to the car, I noticed the parking lights were on, when I got in the car, I found I had left the car unlocked in the battery turned 'on' position. I also have a radar detector hooked up to the cigarette lighter fuse, which was on as well and draining power.

When I hit the 'Start Button' for the keyless go, the battery did not have enough juice to fire up the engine. I tried twice/thrice, and when the car did not fire up, I called for help. The facility I was at, assisted me with a jumper module. When the person hooked up the jumper, I hit the Start button, but nothing happened. When that did not work on 2/3 tries, I removed the 'Start button' and used the key to start the car. The car fired up. I thought since the battery was low, it may have turned off some ' convenience features' momentarily. I thought those features will resume once the battery charges up after driving 20/30 miles.

I drove about 100 Miles back home, when I turned off the car, I inserted the Start Button back into the console, but those keyless features did not work.
1: Keyless Start Does not work
2: Keyless lock/unlock does not work

I have hooked up the car battery to a battery charger, I am waiting for the charger to finish its operation.

After about two hours of the car being hooked to the charger, I tried to use the key fob to lock/unlock the car, but it did not work. I also tried to lock/unlock the car using the spare key (never used this key before), but that did not work either.

Once the battery is charged up, I will use a diagnostic tool to look for errors, and also try removing the +ve terminal for 10 mins to see if that resets the error.

Other than that, is there anything else you can recommend?

Thanks in advance!
Manish

manishjain24

Update: Removing the Battery Terminals for 15 minutes did the job. The software reset must have been the key. I am now able to successfully use the Keyless Go functions. Yay!!

1: Remove -ve terminal followed by +ve terminal
2: Waited 15 mins
3: Reconnected +ve Terminal first, followed by -ve Terminal

juanmor40

These are computers on wheels.

When common sense does not work, just disconnect the batteries, give it some time and reconnect. I wonder if they should have a "Reset Button" slightly hidden behind a switch door like a normal computer

manishjain24

I agree with you.

With the car, these days, having so much onboard electronics it would definitely help if there was a "Reboot" option to safely recycle/reset power much like the Cellphones and Computers. This will prevent the hard reset, which may cause other issues to the electronics or equipment.

To be quite honest, I thought I had fried a module or something else when I tried starting the car on low battery or when I hooked up the Jumper module to push juice to the car.

While these are expensive cars, I am glad I own one, they are built rock solid!!

juanmor40

To be honest, long ago before owning MB I had decided not to jump cars anymore unless no choice. I got burned with GM alternators Delco diodes (70's), Renault's Valeo "electronic regulators" (80's), and once a Corolla Denso alternator (90's) as well.

I disconnect the batteries, charge them disconnected if I have a charger, or take it elsewhere for charging. Not worth the pain of a damaged/fried component.

A horror story with a W166 jumped incorrectly , $4K in repairs instead of two Uber's fares, or worse a towing fee.

kajtek1

In my Sprinter - dealer's mechanic try to crank the engine with low battery.
The result was fried ignition module = $800 part + labor + 3 days down before mechanic found what he screw

BenzV12

Sorry to hear that , I didn't know those things were that sensitive to low battery

kajtek1

This is 1st such incident in long years of driving digital MB, but it did happen.
I had MB cars and SUV jumped in the past and nothing happened, so don't know if that was just Sprinter, or just bad luck.
But the truth is not to force the jumps and be very careful when you do.
When in the past I did not hesitate to scan vehicles on their battery, now when I plan few minutes of scanning, I am hooking up battery maintainer.