High transmission level

2017 Toyota Tacoma, 71k miles. Regular oil changes/service.
1 1/2 yrs ago at 60k, New plugs, Trans flush, rad flush.
Ran great until last week.
Was pulling out of driveway and truck made a sound like a metal spoon was banging in a metal cup, truck shuttered, flashed "high transmission level" and died. Got it started and backed into driveway. Started it later that day, and got it the 100ft to the side of my house.
Next day I started it and after abt 30 secs, there was a noticeable "knock" coming from engine cab.
Called tow truck/mechanic and when I started it for him, the check engine light came on and stayed on, (yellow).
He called this week and his preliminary thought was valve, requiring a total tear down.
I do not know him, he is a friend of another mechanic, that I trust, (he doesn't to major repairs).
I'm at a loss... how do we get to a valve issue, when " high transmission level" light was the first indicator, of something wrong.
Any and all advice is appreciated...

 

Pull the code….

 

There were several.
P1603
P1604
P1605
P0300
P0306
C1268
B1507
B1508
I suspect the last 3 are from last year when I replaced a drivers side front turn signal bulb, and never cleared the code.
I did speak with the mechanic since the first post.
He's going to check the #6 spark plug to see if it somehow came loose.
Those other codes are more geared towards engine and not Trans.
This is going to be interesting to see how this all shakes out...
Any ideas?

 

I'm not sure I know what 1st Gen means. Did I post in the wrong area, for my query?

 

Yessir but you're not far off. 1st gen is 95-04 MY Tacomas. 2nd gen is 05-15, 3rd is 16-23 and 4th gen is the current model (2024-) The third gen group would be able to provide more info

 

Over here-
https://www.tacomaworld.com/forums/3rd-gen-tacomas-2016-2023.186/

 

Don't think bulbs are ECU monitored.......

 

Hmm... maybe misread the screen, I see a reference to high transmission temp but no level.

 

Who did the transmission flush?
How much fluid came out?
What fluid did you fill it with ?

 

Happens all the time start a thread and never report back.

 

It's hard to keep track, she started 2 different threads with the same name.