Hi,
I have not used my truck for about 18 months but kept it started fairly often and moved around once in a while.
Recently I put it back on the road. Had to do a few items, brakes, fuel pipes, fan clutch, thermostat, clean up
the plugs and coil packs and an oil change.
I also installed a new battery and cleared every code in the various modules.
It runs fine and has no check engine light on and the scan tool shows no OBD triggered codes.
After about 100 miles its has cleared all of the ODB monitors except EVAP.
So I put the scan tool on and read all of the modules. The Drivetrain module was the only one to
come back with any code. 24 of them !!!!! Yet none have triggered the CEL.

Here they are: P0442, P0451, P0454, P0464, P0483, P0741, P1816, P0894, P2771, P0131
P0133, P0135, P0137, P0138, P0141, P0420, P0751, P0752, P0756, P0757, P1133, P1400
P2119,P2770

I thought at first it was possibly a bad ground or dirty PCM connectors, but I've inspected, tested and cleaned and found nothing.
When I clear them, after several days some or eventually all will come back.

I also inspected underneath for rodent damage because I have seen a chipmunk jumping on top
of the tire now and again, couldn't find anything.

Any ideas or pointers to known issues that have a common thread with some of those codes. ?

ps. These codes are definitely current codes, not historic ones.

Regards, Alan