CCamp88

Hello,

First off this is my first time using this forum.

Anyways. I have the following problem with my 2007 2500HD.

About 4-5 months ago my check engine light came on so i stopped by AutoZone and borrowed the scanner and found the P0984 ( or something similiar) Transmission Slipping Code (this im positive whatever the number of the code was). That being said the only thing i noticed with that was the "hard" shift engages, which would set after going above ~50mph in OD. I did some research and found that was the ecu/computer detecting a slip and would set into a default/fail safe mode. Was told this could be caused by a numerous things. I took it to a chevy dealer who hooked up the diagnostics and they said the Torque Converter was shot. Well they first said they could replace it for 1200$ or so but later they said 600$. Also this is just after being covered under warranty, as truck is just over 6 years old with 65K miles on it. Before having them replace it i decided to check a few things myself as i do have mechanical/electrical experience, and also was not experiencing any problems (as far as i could notice) aside from the "hard" shift. This made me believe it was a faulty sensor, or fluid level etc. I added about 1 pint of Lucas Trans Fluid Additive and checked all wiring connections, cleaned them (Throttle Position Sensor, Solenoid on Transmission, etc..) After doing this the fault cleared and I have had 0 problems until today.

it has been a couple months and now have 72K miles on the truck. Today while backing up into a parking spot at the local Wal-Mart the truck began to spudder and stalled out. I had the wheel turned sharply and had it in reverse. I checked the powersteering fluid which was low, thinking this could have caused the stalling problem if something else such as fowling plugs, dirty air filter etc. After adding fluid, checking plugs, wires, fluids etc. I decided to risk it and drive back home. While driving home i experienced no problems until getting on a straight away going about 50mph at a "cruising" speed in OD and came to a hill and began to accelerate at which point it was as if the torque converter was unlocked (the truck would rev higher RPMs but not accel. as it would do if in Neutral). I managed to drift to a pull of spot at which with out turning the truck off, shifted to 1st and manually shifted 1-2,2-3,3-D and it continued fairly normal. Upon coming to the mountain i have to cross it pulled upwards fine until the 4way stop at the top. After taking back off at the stop, in D it would rev. higher than usual RPMs before shifting. Then made it back home without problems.

From what I have been told, and what i seem to be expeiriencing is this is some type of Torq. Conv./Transmission problem. I have yet to hook up the OBD2 and read the new current code but will do as soon as i can and will post then. Also, i have never flushed/changed transmission fluid, aside from adding the 1 pint or so of additive. Could dirty/worn fluid becausing all of this? Will a flush/change possible cure problems? Anything further i can do myself ? The reason i ask is i dont want to dump the money in a new torque converter and still have problems. From what ive been told before, there still could be something fairly simple/minor (by simple i mean, less serious than a new torque converter) such as bad sensor(s), fluid needing changed. etc. I would greatly appreciate any feedback from anyone with past experiences with this or similar problems. It is just frustrating as the truck, in my opinion anyways, is still fairly new with only 72k miles, has never been put under any real load like pulling/hailing anything, and is and "HD" which is supposed to be Heavy Duty?

Thanks/Regards


CCamp88

tech2

post the dtc that have set. Diagosis must begin there.