Still trying to diagnose the transmission shifting (OD & TC).

There seems to be no rhyme or reason as to when the transmission decides to shift into OD. Sometimes @ 35mph, sometimes @ 45 and other times @ 50 mph. Sometimes if I let off the throttle completely, it will shift into OD. Once in OD it stays. I installed two LEDs that register the ground signals from the PCM for OD and TC lockup and they both light up when driving OD 1st and TC later. I contacted DTT (I have their valve body installed) and was told to adjust the TPS to 0.9vdc and it still acts the same (replaced the TPS approx 10K ago). I have installed the DTT noise filter with no change. Just had the transmission serviced with no difference.

Any other ideas? I'm going crazy.

Mike
1996 2500HD w/47RE

 

adjust your throttle linkage .. if its off ir will mess with your tps position and such ..

also make sure your TV cable is adjusted correctly ( youtube can show ya how ) ... LOL

 

FIXED IT!!!!

TV cable adjustment. I had paid a local Diesel shop to adjust, was told by shop owner it was done, NOT even close!! I adjusted it and all works well. So much for reputable shops.