Lost TCC control signal?

[Matthew Jeschke]

I am on a road trip and got DTC P0741 TCC stuck off. I have a bidirectional scan tool with me. I can command the TCC on just fine but for some odd reason the computer will not turn it on itself. Any ideas gas mileage is horrendous without the torque convert clutch locking up.

Thanks!

 

[rockola1971]

Speed sensor reporting? When you are commanding TCC On, is this while moving or sitting still? Just because you commanded it on, doesnt mean it is actually on at the solenoid. If you were moving and commanded it on, did you feel it engage and your RPMs drop?

 

[Matthew Jeschke]

I figured it out. I was tuning and set the minimum tcc pwm to same value as tcc maximum pwm. Both set to 100% duty cycle in attempt to disable tcc partial apply. The computer couldn't figure out how to handle that so it just disabled tcc all together.

I need to figure out how to best tune the TCC. I notice even from factory TCC can and does provoke knock. Trying to also balance that out.