So yesterday I was driving around (taking it easy...really), and everything was normal (80 mph @ 2000 rpms). On my way back from nowhere, I noticed that my rpms were at 2100, but I was only doing 75mph. WTF??? It still felt normal at slow speeds, shifted ok, no real reason for alarm.

This morning, I pulled the codes, and this is what I got.

P0740 - Torque Converter clutch circuit malfunction
P0753 - Shift Solenoid A Electrical
P0758 - Shift Solenoid B Electrical
P0785 - Shift Timing Solenoid Malfunction
P1860 - TCC PWM Solenoid Electrical Fault

Something tells me that this is not too good. The truck is tuned by W4M. I had him bump the line pressures, but the rev limiter is the stock. Is it possible that something went wrong with the tune? I am not trying to assume anything, but I figured that I would ask.

 

I don't know all of your ratios, but I have stock tranny ratios, 3.42 rear and stock height tires and @ 2100 I'm doing 74mph

Anyway, as far as your codes are concerned, it sounds like your TCC is not locking up, thus the higher RPM value.

Have you had the pan off for anything?

 

3:73 rear, stock tranny, stock tires LTs, ory, flowmaster. Since the day I got it, its been at 2000rpms at 80 mph. It does sound a little off, but I can't argue with the truck.

I haven't had the pan off for anything.

As for the TC not locking, what could cause that, just out of the blue like this? Tuning issue? Its been tuned and running fine for months now (5?), I don't get it.

What steps does the truck take to lock the converter?

 

Check the main trans connector. Make sure it's plugged in and snug. Sounds like you're not getting power to your trans' electronics, and it went into limp mode.

 

with all those codes?? limp mode it is... check your connections, erase the codes, and keep rollin