Tcc unlocking !!!

907dragdiesel · New Member Joined: Apr 11, 2008 Posts: 15

We have the trans pretty well dialed in ,, we are now trying to find out why the TCC would unlock all of a sudden under hard acceleration ..

It willl hold until the motor really starts loading ,, as soon as the boost starts to hit the clutch unlocks and the trucks acceleration falls on its face ,, If you slowly roll into it it seems to hold OK ...

I think it might have something to do with the MAP calibration ?????

mo_smoke · Junior Member Joined: Sep 20, 2007 Posts: 25 Location: NH

I don't use the MAP or ECT, just the TFT, RPM and all of the other trans sensors and works fine...Just need to firm up the shifts a-bit.
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Russ · PCS Employee Joined: May 12, 2004 Posts: 286

Try setting the Lock Up Ending Duty Cycle to 100%. This will ensure maximum line pressure is getting to the lockup clutch. You can also try increasing the line pressure and see if that helps.

Russ

907dragdiesel · New Member Joined: Apr 11, 2008 Posts: 15

I found the problem yesterday ,, I didnt have the problem when the motor was completely stock ,, the problem started after I tweaked the pump and installed the boost elbow ..

Anyway the failure default settings for the MAP sensor were set for when the motor made 16PSI ,, now that the motor makes 30 PSI it would trigger the failure setting and unlock the TCC ,,, I set it for a higher voltage and everything works great ...

The truck now holds and makes 32 PSI accelerating ...

Thanks for the tips ..