Had this issue like 5 times in the last month or two. Car sometimes won’t shift when trying to shift from drive to another gear. Car doesn’t have any issues when driving shifting gears 1-7, only when shifting at a stop.Anybody experiencing this?

 

This is related to the IntelligentShiftModule going into limp mode.

Have you seen a message saying "drive to dealer without stopping..." ??
This is the shifter warning it is in the mood to lockup "PRND" into Park.

Best thing to do besides driving to local dealer is scan the chassis to read active faults.

Identified causes are soaked connector and failing solderless pins. AUX Batt is involved in that circuit and may provide additional upsets.
So don't rush replacing expensive parts before troubleshooting.

 

I have not seen that pop up no. Now that I think about it, I don’t think this ever happened before I replaced the auxiliary battery about a month and a half ago. Do you think a faulty auxiliary battery could play into this?

 

Yes, MBs' electronics are very voltage sensitive, a bad aux battery can cause transmission issues.

 

yes definitely a possibility if AUX Fuse was blown to begin with and new AUX is not being charged while driving - Then you'd get AUX Messages shown on your IC Display.

You can measure voltages with a simple DVM but won't go real far without using a scanner to read OBDII port.

The good news is you may not have a bad ISM if AUX is dishing out all the troubles.

At some point use a CTEK float charger when car is unused. This will automatically preserve both your batteries in top condition like new.

 

As mentioned above, you must scan the vehicle with a decent MB-aware scanner. Once the scan results come back, please post them.

I would not be surprised if you will see something similar to (https://mbworld.org/forums/e-class-w...ml#post8707959)

 

Juan: that is a great must-read reference thread for this topic.