I have P0442 and P0455 codes (EVAP codes that I've known about for a little while) showing with the key trick. I just bought an Innova code scanner to retrieve any pending codes and got P1740. I kinda wonder if these codes are related, as if the PCM is looking for a particular vacuum signal to engage TCC lockup.

Truck info: 5.9 liter, harland sharp 1.7 rockers, timing advanced via crank position sensor, reamed out throttle body, 4.55 rear gears, custom 3"single pipe exhaust, 180* tstat, and other little things.

 

P1740 TCC or O/D Solenoid Perf

There ya go.... Check all the connections first, at the trans, and also check the PCM connectors.

 

Well, I dropped the tranny pan and found broken pieces from the boost valve, this being part of the lockup circuit. See this video:

Dodge 46RE OBD Fault Code P1740 Torque converter lockup solenoid/relay - YouTube

Anyone know where I can get an upgraded boost valve assembly in Ontario, Canada? And, has anyone here ever put a rod in place of the accumulator spring for firmer shifts?
Thanks in advance!

 

Try WITTRANS.COM

I dont know if they ship to canada or not..... I would think they do.