Conductor assembly replaced...post repair problem

[JAD]

1999 ML 430

I recently had my conductor assembly replaced to solve a long term transmission issue. All seemed good. In the first 30 days following the repair there was an issue on 4 or 5 separate mornings ONLY during the first cold start of the day (started after sitting overnight). It never happened while driving the car around town or parking and restarting with a 4+ hour break. After sitting overnight and then starting the car I'd let the RPM drop to around 750. Then when shifting into R or D and pressing the throttle the car wouldn't move for a couple seconds, then it would pop into gear. The problem has been very intermittent and hard to reproduce. The last time this occurred after starting, the truck was going in and out of limp mode while I was stop and start driving around town. the problem seemed to be cascading and getting worse, it had not done before in the last 30 days.

Took it back to the Mercedes only indie, no codes. Right before I had the conductor assembly repaired (car was sitting for several months before this repair), I also had part number 210 545 13 32 (part number 74 on the PDF) replaced by an so so mechanic. I'm wondering if he screwed it up or screwed something else up when attempting the repair.

The indie isn't sure what the problem is yet, right now he thinks it's either the shifter/gear selector mechanism or the TCM. If it was a problem with the gear selector switch I had replaced, wouldn't it generate a code? As there are no codes present, the mechanic said it has to be something mechanical or the TCM going bad which wouldn't generate a code.

Thoughts? I'd like to help point him in the right direction if possible.