[mooginfee]

Hi guys thanks for having me here. I am at my wits end I have a 95 f350 powerstroke 4wd automatic transmission. To start at the beginning the stock tranny while driving down the road when you let up on the throttle would seem to go into neutral and when you pressed the throttle to go the engine would just rev up. If you slowed down to about 20 mph sometimes it would go back into 2nd gear and go on. Sometimes you would have to manually shift down into 2nd gear to get it to catch then go on. Sometimes this problem would cause it to go into limp mode and then shift hard on the next shift pattern. We are now on our 3rd (yes count them 1,2,3) jasper remanufactured transmission (not counting the factory tranny) and it is still doing the same thing. I believe the problem is somewhere else. We have replaced all sensors relating to the transmission and all work has been performed by a certified master Ford tech. Somewhere I seen a post that said that the brake lights and turn signals and dome light are on the same circuit as one of the tranny sensor circuits and can cause shifting problems. It is kinda an intermitten problem and does not do it all the time. Please, Please help this is getting very expensive and I am out of ideas.

Merry CHRIST-mas everybody and GOD bless.

 

[Relentless007]

Have you checked your transmission control module (TCM) (electronic control box on the inside of the driver side fender by the firewall) and the speed sensor on the rear end?

 

[Mark Kovalsky]

When it went into limp mode what codes were stored in the computer? Without codes it's going to be very difficult to diagnose this problem.

 

[mooginfee]

Have you checked your transmission control module (TCM) (electronic control box on the inside of the driver side fender by the firewall) and the speed sensor on the rear end?

Yes we did change the control box on the drivers side inner fender that has the connector with the screw on it. It got fried when our injector harness plugs shorted out on the valve cover gaskets but I'm wandering if maybe it could be going bad. We did hook up a trailer brake controller. Could that be dropping the voltage on the brake light switch circuit causing a problem?

 

[mooginfee]

When it went into limp mode what codes were stored in the computer? Without codes it's going to be very difficult to diagnose this problem.

Hi Mark thanks for the response I read somewhere else on here that you had "type F coursing through your veins". I will call our mechanic and get the codes that he read and post them back here.

 

[mooginfee]

Ok guys been a while since I've had a chance to come back. So while I was gone and hopefully not jinxing myself but I had read some posts about how these trucks have given other people trouble shifting when something is wrong with the brake light system or dome light system, I thought back to what all we had done to the truck after we purchased it until it gave us tranny trouble. One thing that we added to the truck was a trailer brake controller. In this installation you have to piggyback a wire on your brake light switch to activate the controller. So putting 2 and 2 together and coming up with 14.7398 (random number) I thought maybe this is somehow messing up some signal that the tranny is receiving causing it to act up. So I unhooked the brake controller completely and ran the truck all the next day hauling 4 loads of gravel at almost 4 tons each about 10 miles each trip and had no trouble at all that day and have driven it a few other days and no trouble then either. So maybe there is something these guys are hitting on when they say the brake light and dome light circuits are the same or mingled together in the fuse box or something I dunno. All I do know is that I have said a lot of prayers over this truck and I think GOD has finally answered them in HIS own time. Thank you LORD!

 

[chuckster57]

What brand of brake controller are you using? Pretty much all aftermarket controllers use the "cold" side of the brake pedal for signal. By cold side I mean there isn't any voltage present until the brake pedal is pressed.

 

[Relentless007]

maybe your controller is pulling to much voltage thus causing low voltage on that circuit which would result in computer faults. <--S.W.A.G. only way to verify is to test with and without controller