Transmission problems acts possessed

Okay so basically this is what is going on with my transmission.

I have a 2007 Toyota tacoma 4x4 DCLB 4.0 V6


I first started to get these issues about a week ago.


This is what it will do.


When starting engine and shifting to reverse it will not go into reverse it acts like neutral.


Truck will go into drive but won't always shift through gears right.


After driving for a little bit when I decide to park it sometimes will shift to reverse when I ask it to.


Sometimes while driving it will shift funky like It won't shift into 5th or will stay in fourth or stay in first just randomness.


Things I have done.


Put in a newer transmission


Changed the solenoids


Checked wiring harness for any imperfections and also checked resistance on wiring harness


Made sure all grounds were connected correctly.


I have hard reset the computer


Transmission fluid has been completely emptied and properly filled with new transmission fluid.


All fuses are good


All connections on the wiring harness have been cleaned and electrolyted and properly connected.


I have also hooked up my computer to the truck and I am able to turn the solenoids on and off with the computer and it will shift into the gears correctly. So I do not believe i have missed something on the wiring harness and I am not to sure of it is the ECM




Any help on this would be greatly appreciated I have been losing my mind over this.


DURANT Toyota in Weatherford TX has basically told me to go eff myself. I have taken it up there to them and asked them to look at it or run diagnostics to see if the ECM is bad. They acted like I never asked the first time. The second time I went up there they told me it would be a $500 diagnostic fee because its a "complicated" issue and it would take around 4-5 hours of labor to use their high tech diagnostic computer to find out the issue. (Not a joke that's what they said)


Please help somebody has had to have this issue.

 

How 'new' is this tranny? Did it work fine at first, then start to act up? What was the problem with your original tranny? You might try to borrow someone's computer from a same model truck or get one from a salvage yard and try that. If that doesn't work then you know it's a tranny problem.

 

newer tranny has about 40,000 miles the older tranny was grinding gears a bit and it needed to be replaced it was pushing 130,000 miles, i took it out last night the newer one is doing the same thing as the old one just without grinding, it wont shift like normal. its popping up a P0976 code and a p0973 code i have done literally everything except get a new ecm, but can an ecm just crap out randomly?

 

So this newer tranny started doing the same thing without grinding right away. Almost sounds like a pre existing problem. Those codes are for low voltage to solenoids, but what would cause that?

 

This is just me, but your best bet would be to find another dealer and see if they would give you a more refined diagnosis based on those codes.

 

Just a shot in the dark, but have you checked the easy stuff? For example, your transmission filter and fluid. A clogged filter can cause some pretty strange symptoms. I do see you've changed the fluid, but did you use the right fluid for your particular transmission (the fluids are not all the same)? Beyond that, I have nothing. Odd problem. May need a transmission expert. Good luck.

 

Yes I used the right fluid, the new transmission is not grinding. The transmission is just shifting retarded

 

Not sure of which years but there was a TSB about some shift issues with the automatics that required "flashing" the onboard CPU

(reprograming/updating) Check to see if yours requires this...

 

Ecm was flashed today no luck. Possibly a grounding issue?

 

Reverse in the Aisn Warner A750 is mechanical ,not electrical or ECM solenoid controlled . If you are not getting reverse I would be looking at the control valve body .
If you are getting good reverse but your upshifts are messed up , find out why those codes are coming up .
The newer transmission will do the same thing because the ECM sees an issue with the wiring going to the transmission and commands your transmission into fail safe
The computer is designed to prevent any further damage to the transmission .
A private subscription to all data may be what you are looking for to diagnose the problem .
All Data is about the only company that can give you a Toyota electrical breakdown for the transmission control circuits coming from the ECM .
https://checkout.alldatadiy.com/ade...ke=121914475&model=121914587&engine=121914593

If I had to guess , you have an issue with the wiring from the ECU to the transmission .
Are you any good with a DVOM ?
http://freedownloadb.com/pdf/ba750e-b-and-a750f-bautomatic-b-btransmission-b-3220218.html

 

I have all data and have been using it religiously. I'm heading to the shop now to see if its a grounding issue. I think it's something small I'm over looking

 

I'm okay with a dvom. I see more practice In my future....

 

Yes, an ECM can just crap out randomly. That being said, you have to rule out any other possible issues. Remember that when you are driving your truck, vibration can cause intermittent loss of connections with terminals, or if a wire is worn, and close to shorting, vibration may cause it to make contact and short out. When you run your diagnostic checks, I suggest you look from the harness where it plugs into the transmission, and follow it all the way up to your ECU, looking for possible points of rubbing through, or kinking which can cause internal wire breakage. Putting your multimeter on an audible "min/max" setting can be very helpful, as it will beep at you when you cause the short to occur (if that is the actual case)

A failed, or failing ECU can cause all of the problems you mentioned EXCEPT for no reverse. As mentioned, a valve body can cause this issue. Also a misadjusted shift linkage can do this as well. Check with your available information to find out the proper procedure for adjusting your linkage. Look on the side of the transmission also for a loose linkage condition.

Shorts, open wires, and failed internal diagnostic connections can cause that.

AllData is pretty good, but here at the shop we use Mitchell1, which also gives very detailed diagnostic information taken directly from Toyota.

Definitely learn your DVOM. What kind do you have?

 

It's a Mac tools dvom.

Truck is popping up a ton of different codes now

 

I used my dvom all my resistance is good went over all my grounds cleaned them reconnected them. Now I'm popping up these new codes. I'm so lost

 

Did you hook up the linkage correctly

 

left the house this morning to take it to Vandergriff Toyota in Arlington all the way to the gas station it stayed in 3rd got gas then i asked the truck really nicely to please shift into 5th on the way to Arlington (30 mile drive) .........it drove like it was new....im sitting at Vandergriff right now they are taking a look at it.

 

Linkage i did make sure that was hooked up correctly yesterday forgot to add that.

 

I'm getting from Toyota that the transmission is bad.