this my first post. I am having a problem concerning my transmission.
When driving at times I lose power to the drivetrain. Engine continues to
operate properly(rpm drops off). I had the transmission fluid and filter replaced. Also had the speed sensor in the rear end replaced. Seems this
problem occurs when they don't have their computer connected to the truck.
They have drove it and can't get it to happen. This morning it happened again.
Having read a few posts and relpies I noticed if the back up lights don't work
it could possibly be the torque converter sensor. Before taking to the mechanic I was wondering where the back up light fuse it located.(manual does not show one). thought I should check this, before taking before going to the shop.
Remember this an intermittent problem.
They also replaced the sensor on the side of the trans. and that had no effect on the problem.
They said the only fault they found was the speed sensor.
Any suggestions will be greatly appreciated.
Thank you

 

First of all....Welcome to FTE, I'm sure someone will have the answer you a re looking for.
Does this mean the trans is slipping?

Since this is intermittent it could be an electrical problem or mechanical or both.
Check all of the connectors on the trans, remove them and look at the condition of the pins and sockets.

I'll ook for the backup light info for you.

EDIT: Describe your truck, year engine, milage and any mods ect.

 

Back up lamps fuse is #5 in the under hood fuse box.
15 AMP

 

the transmission does not slip it just loses all power to the drivetrain. i can wait for it to go down to a slower speed and it will engage. i can manually go thru the gears and it runs properly. seems to have a problem when in od with
the cruise on.

 

Does the engine die too?
If so, It may be the CPS, even if it's new.

 

fuse is not blown and still no back up light.

 

engine operates ok., just when losing power to drivetrain rpms. drop off.

 

I don't think the backup lights will cause this.

Check the bulbs or see if power is getting to the sockets.
These usually get rotted out.

 

Take a look at all the fuses under the hood. Be sure they are tight...no corrosion.
Especailly #22 and #9.

 

Does it feel like the cruise control is just kicking out by itself?

 

Sounds possible to be brake light system related.

Bill

 

Sounds like the Trans Range sensor. IF they put one on and did not adjust it corectly the the will cuase you to have not back up lights. There is a whole on the side of it that you stick a pin through I belive. I am not 100% on how to adjust it but ill look it up for you or someone else might know. But I would do what cuda said too and go from there.

 

he already replaced the trans range sensor but back up for a minute..... he says it loses power to the drivetrain and the engine rpms drop off????? that doesnt make sense to me. are you saying the truck returns to idle?or does it act like you are letting off the throttle? that is what it sounds like you are describing to me anyway, and if so then i would look more towards a tp and ivs sensor. they wont throw a code but the pcm thinks you let of fthe go pedal.. correct me if i misunderstood your issue but that is what you are describing to me when you say the engine rpm drops off

 

i looked up tp sensor but i can't figure out what the ivs sensor is?
they will repalce transmission sensor tomorrow because i have no back up lights.
they keep saying to drive it until it fails again, then bring it back.
losing power to drivetrain,it acts like the transmission is going out and no power to pull truck.(not good at describing).
the speed sensor is new,that was first code, and no other codes detected.
some one told me about the tp sensor but again they will not listen.
if it don't throw out a code for it , how do you know it's bad, and where is it located?
is it something i can replave myself?
main question is what is a ivs sensor and where is it, and what is it function?
thank you

 

Check fuse #3 under the dash it protects the IVS

TPS = Throttle Postion Sensor
IVS = Idle validation sensor. As the name implies, it validates when the go pedal is
in the idle position.

The IVS is on the TPS. It on the accelerator pedal.

You don't want to buy one, they are very expensive unless the prices have changed.
Be sure the connectors are tight.
You can remove it and clean both TPS and IVS....and adjust the IVS if necessary.