Range shift inhibited

[E.carter]

Went drag racing yesterday and had some issues..... Forth pass I lost reverse and got some dtc's P0700, p0878,p0978. Thruck was also starting in third gear? I cleared the codes and checked the harness and reverse came back. Then the codes came back and I lost reverse again, but had all forward gears. I have not had much time to reserch myself very busy weekend..... The only code that keeps coming back is p0878. Any help would be great. My set up is in my sig

 

[Mike L.]

I would check with tts. I have no idea what he does in his upgrades.

 

[E.carter]

not even a guess mike????? I am not feeling real good about this issue

 

[Mike L.]

not even a guess mike????? I am not feeling real good about this issue

You need to tell me what you did inside trans and what you used before I can guess.

 

[E.carter]

Pump spring shim, transgo jr valves, machined c-3pressure plate, extra clutch and steel, planatary spacer,converter flow valve. I installed it at about 14,000 and now have 25,000. I have had zero issues with it until now.

 

[redws6rocket]

have you changed your external filter!!! i have run into that code and a plugged filter!

 

[E.carter]

will do that in the morning and get back at you

 

[JoshH]

Based on the codes, it sounds like it could be an electrical problem. I had a similar problem with my truck losing reverse once the fluid was warm. It ended up being a problem with the pressure switch manifold that attaches to the bottom of the valvebody. I swapped it out and haven't had a problem since.

 

[Mike L.]

Could be the pattern switch ( internal NSBU ) not agreeing with selected gear on shifter which could indicate bad pattern switch or like Josh said, a bad PSM. Could also be internal/ external wireing harness problem or a sticking valve in the valve body.

 

[E.carter]

Thanks guys for the pointers..... I will try and do a little checking tonight if I get time to drop the pan. IS there anything that can be adjusted with the nsbu?or something I may have screwed up putting it back together? In the past sometimes when I put it in park and shut the truck down it would make a kiknda loud knock or snap like it finally fully engaged park???

 

[Mike L.]

With the mileage you have already put on it I doubt you did something wrong. It would have acted up right away.

 

[E.carter]

Thanks everyone for the input..... I cant believe how dumb this whole issue was. Took apart the trans external harness, cleaned it, smeared dielectric grease all over it and reconnected and found that the thing does not latch to the trans anymore. I will try to see if the connector is a service part and repin a new connector as I dont want to put up with it coming apart at the wrong time again. Its great to know if a member has an issue that so many will help with what knowledge they have.