Intermittent problem selecting gear on starting - transmission 722903 03

[such]

I've had a problem with being unable to select D (or any other gears) when starting which occurred maybe once per month over the last few years and it has now progressed to a couple of times a day now. If I remove the key and restart it usually works the first time, although on the odd occasion I've had to do this a couple of times in succession.
This can happen if the engine is hot or cold. All other gear changes when moving have been fine.
I've scanned and got the following codes whilst it was not selecting gears:


Can anyone shed some light on this please and suggest a starting point of where to look please?
Thanks

 

[onefortheroad]

Try another key.

 

[such]

Thanks for the suggestion - I had a new key made recently due to a dead dash issue which was initially thought to be the ESL, but upon investigation, It turns out I don't have an ESL and the spare key worked.
I'll try the original spare key but I was having this problem before I had a new key.

 

[Uncle Benz]

The fault is coming from the gear selector module that’s bolted to the side of the gearbox. They are normally very reliable. If your battery is old I’d recommend replacing that first. I’ve seen selector faults occur erroneously when battery has been weak many times

 

[malcolm E53 AMG]

Very possibly a fault with the ISM

 

[such]

Very possibly a fault with the ISM

Thanks - not had any warning messages as seen in this video or any of the codes mentioned.

 

[such]

The fault is coming from the gear selector module that’s bolted to the side of the gearbox. They are normally very reliable. If your battery is old I’d recommend replacing that first. I’ve seen selector faults occur erroneously when battery has been weak many times

My main battery is approx 3 yrs old - the aux battery is the original - 12yrs old now.
I did read online that the first port of call is to check the aux battery first. I'll get that checked.
Thanks

 

[malcolm E53 AMG]

My main battery is approx 3 yrs old - the aux battery is the original - 12yrs old now.
I did read online that the first port of call is to check the aux battery first. I'll get that checked.
Thanks

Give the main battery a good charge as well

 

[such]

Try another key.

A quick update - tried the spare original MB key and have had no issues now for over a week. Looks likely that the issue is with the new key.
I have referred this back to the company that made the new key.

 

[onefortheroad]

A quick update - tried the spare original MB key and have had no issues now for over a week. Looks likely that the issue is with the new key.
I have referred this back to the company that made the new key.

I had the same issue ,. It's the key flashing process or cheap Chinese PCBs they use. ?

The gearbox module is one stage of the immobilizer system.

 

[such]

update - the original spare key which I have been using since June is now doing the same thing - had a couple of issues with selecting gear on starting which resolved upon restart.
is it possible that both keys, being 10 years old, are now faulty?
I never did go back to the company that provided the new key since I was using the original spare.