it all startd pullin my horse trailor loaded wouldntdown shift going up hill from a complete stop had to drop it down to manual2 to get it up the hill.by the time got truck to barn it wanted to over heat.droped trailor went back to the house. did better with out load. ordered a new throttle position senseor for it.installed it. truck is now in second gear will not shift up or down. it blew a 20a maxi fuse for ecm power replaced itstill not working correctly.went to pull more codes no code.need help.tranny is a 1yr old jasper e40d

 

I am dealing with the same thing!!!!!! I haven't blown any fuses but my shifting problem are the same. I noticed that if my running lights are on, it won't do it and it runs just fine but won't do the shift crazy as much very few times, shift just fine up and down.

Im also pulling a trailer, happens way more with trailer and very very rare happens without it. Thought it might be my trailer messing with it somehow till it happened without it.

I have tried everything and look everywhere and nothing. I changed my TPS and it did nothing with no different.

I am waiting with you for someone to help with ideas or places to check, good luck!! Thanks for any help.

 

you are back feeding your brake lights, check all grounds on trailer and bulbs on the truck, your trailer brake controller can blow fuses.. you can't use LED bulbs in the truck as it fouls up the PCM for E40d ground path must be good thru the trailer plug..

 

I have LEDS all over the back of my truck, and trailer is as well. On the led's there will sometimes be one or two little bulbs on the brake lights ones that stay on when truck is off. Have never been able to fix and have just learned to deal with it.

How do I fix back feeding it?? Is it just grounds messed up? Where is the E40d ground path at???

 

I also have led light on my truck and it is the same with some of them staying on when the truck is shut off. I was told by a mechanic to buy a new engine wire harness, but it sounds like I may not need one. Any help on the grounds for the trani would be great

 

Now, if I turn the a/c on it messes with the transmission, soon as I turn it off its fine. Its getting worst. turn the running lights on its fine. Lights turned off sometime under load with trailer, does crazy shifting, starting to make me mad!

Does anyone have help with any grounds for the transmission or what I should be checking or looking where?? no blinking light or any light

Thanks everyone..