Does the transmission feel like it surging or the torque converter is coming out of lock up? What were the codes the dealer have pulled out of the TCM? If you are coming out of lock up, when you shouldn't. Could be either brake lite switch or TPS.

 

its not surging, it will shift into overdrive, then drop out like Im accelerating. It will also sometimes not fully engage overdrive, my tach will dance between RPM's like its trying to get to overdrive but something wont let it, and as soon as it engages, pops right back out.

 

That's exactly what mine did. TPS is likely the culprit. $40 at Autozone and if that doesn't fix it, you're only out $40. I found that solution somewhere on this forum. I was skeptical at first about changing it because I didn't see how that could affect the transmission, but since it's all electronic, it definitely does. If the voltage from the TPS isn't steady, the PCM sees that as you either accelerating or decelerating and sends that on to the transmission.

 

ill replace that this weekend and post back my results.

 

+1 on the TPS

 

Ok, so $33 for a new TPS at Advance Auto, put it on, had initial idle surge, even when in drive at idle, major when in park, dipped below 500 RPM's to around 400 before it shot back up to 1000. Drove it for 5 miles, not a single trans problem whatsoever, hit 55 mph for about 2 miles, no overdrive issue. Second ignition cycle, no idle surge, no trans issue, will need to drive more, but so far so good!!!!

Also, my truck has been sitting for about almost 2 months too, started it for the first time today in 2 months

 

you should probably reset the pcm after installing the new parts (just disconnect the battery and hold the key to start for 30sec to a minute)

 

how would the PCM reset like that if its not getting power

 

Believe or not. But all cars and trucks will maintain voltage for 2 mins after the battery has been disconnected. That why when you work on a air bag problem, its recommend to wait 2 mins after you have disconnected the battery. Turnning the key will help to discharge the voltage in the system.

 

Ill do that and see how it runs, but like I said the surging went away as soon as the truck sat for 10 mins and was restarted and driven again. Now I can finally enjoy my truck, 44K on an 03 SLT+