Interesting Tranny issue.

[KC90]

Bit of what happened beforehand... I just finished my timing chains and have the engine in the Explorer and running good since yesterday (with the exception of it being in continuous "open loop" mode do to my dead O2 sensor.) I take a Mechanics course in college so Id thought Id put their nifty reader on my Explorer since it popped "CE" pretty much as soon as I first started it up. The Reader is called a "Genisys"

Codes came up. 2 Engine/PCM and 16 from another system.
The 2 Engine codes were Bank 1 Sensor 1 O2 Heater Circuit fault and Failed OBDII System Drive Cycle( My guess is because of my O2 sensor the computer cant properly relearn its drive cycle)
The 16 were actually only a couple but had come up more then once. Examples are Rear Wiper circuit Fault, Rear Wiper Motor Fault, Brake Light Fault and a few others similar. Also a couple NO DESCRIPTIONS.
Anyways I cleared all codes.

On the drive home everything was fine, it still ran like it was in "open loop" but no CE popped up. Almost home I noticed my RPMs jump from 2000 to 3000. I thought it just upshifted for some reason. while going up the hill to get to my house I noticed it wouldnt shift down, my RPMs would only go higher. I usually back up my driveway so I put it in Reverse but nothing happened. Put it in Drive, nothing. 2nd manual it engages and runs normal. Go back to Drive and it goes out of 2nd and doesnt do anything.

Here is the interesting part, after panicing and thinking "AWWW DAMNIT WHY ME?" I thought the tranny went... So I checked my fluid, all good. Turned off the Explorer and then started it back up. I shifts fine, actually perfect... For about a 1 minute. Then I lose all my gears except manual 1st and 2nd, even Reverse wouldnt engage.

Here's what I noticed:
When my tranny engages R/D/2/1 properly, I can hear the gears click in.
When my tranny doesnt engage R/D, I cant hear any click or pop whatsoever from the transmission( my shifter still pops into place tho.)
When I lose shifting ability, I turn the vehicle off then back on and I regain normal shifting for a short time - about 1minute or so.

I did some searching and I am aware that the 5R55E is computer controlled, leading me to believe when I cleared the codes, I possibly cleared something I shouldnt have. I have disconnected the battery in hopes of resetting the computer, Ill update whether or not it solved the problem.

I would like to know what others think. I found this to be very strange and frustrating considering I havent even had the thing up and running for even 24 hours.

 

[Facimeor]

it sounds to me like a coincidence that your code reading/clearing seemed to lead to a transmission failure. There is no way to "clear" the computer programing that allows the engine and trans to operate at least at a basic level. Whats more likely is that during your drive home you experienced a VB gasket or servo seal blowout. Once the fluid pressure bypasses the blowout it might be creating a backpressure circuit.

Does your fancy reader read trans codes? many dont, but I would check to see if any trans codes are stored. After that a full pressure test would be helpful, likely followed by a visual inspection of the valve body gaskets.

 

[KC90]

Could very well be. I was planning on fluid change and doing the valvebody gasket soon anyways... but not this soon. I found it weird that I regain shifting after restarting the vehicle tho.

 

[KC90]

Well, I pretty much have my mind set. When I gather everything I need Ill do the valvebody repair and replace my EPC. Like I did with my timing chains, Ill try to get decent photos of the progress.

I know Im losing pressure, especially after the transmission warms up. My OD light started flashing and I lost 4th and 5th gears and stuck in 3rd on the way home yesterday. After stopping I lost all gears except manual 2nd and 1st. After restarting my Explorer I gain enough pressure that for a short time I regain shifting. I also know most valvebody gasket blowouts are close to the EPC, I suspect a blowout somewhere else with my symptoms.

Ill make a new thread when I start taking apart my transmission.