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How can I check and / or clear TCM codes without going to a dealer? P0700 and P1731

13K views 20 replies 8 participants last post by  Hemissary 
#1 ·
This thread is relative to my other thread: https://www.lxforums.com/board/tran...n-fluid-drove-car-engine-light-limp-mode.html

So something I didn't think about that I did when changing my tranny fluid is while I had it on jackstands I had my driveshaft off because I changed the carrier bearing. Well when I finished my tranny fluid/filter change I started the car and ran it through the gears with it still on jackstands, no driveshaft connected, and aftermarket wheels on that do not have the tire pressure monitoring units. So considering all of this, when I did get the driveshaft back on, car off the stands and drove if for the first time, could this, along with vastly incorrect fluid level be why I have the P0700 code / some code in the TCM, triggered?

At this point I have purchased Torque Pro and a BAFX Products dongle, added the Torque Pro additional transmission temperature OBD2 PID, and successfully used them to clear the P0700 ECU fault and successfully check my transmission temperature to accurately set my fluid level. Torque Pro also displayed fault code P1731. But now I have a code in the TCM which I cannot clear so no matter the troubleshooting steps taken, see the above link for more info, I cannot get the car out of limp mode.
 
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#2 ·
DTCs will immediately be set for no wheel speed sensor data. These will usually clear when the speed sensor data is updated (after driveshaft reconnect / normal driving and at least one key cycle). However, it is possible that no rear speed sensor data could generate an TCM DTC that relates to final TRANS shaft speed / wheel speed. This could very well keep the transmission in limp mode.
 
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#3 ·
Agree, running it through the gears without wheel speed data probably set the code and put it in limp mode. Even though the wheel speed data is present now, the TCM may be ignoring it until the code is reset. See my reply on your other thread, you're dead in the water until you get a scanner peek at your TCM.
 
#4 · (Edited)
#6 ·
Wouldn't that be great; do we know anyone here at LX that has bought this and can comment? That like three glasses of good scotch...hmm.
 
#15 ·
Thanks to RobsSXT, screen shots of the TCM diagnosis tab;



 
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#17 ·
I bought and downloaded this the other day, and I figured since I have a trinity 2 (which has an obd II to HDMI cable) I'd try out the hdmi connection and see if it would work. It not only did not work, but it got so hot that I actually got burned when I unplugged it. Don't do that.
 
#19 ·
A few days ago I checked continuity of the pins from the female connector where it plugs into the transmission to the connectors at the TCM. All good. Checked cleanliness. All good. Checked for shorts. All good.

For the 2nd time I sucked the fluid out and dropped the pan. Fluid, pan, filter, all still looked good. Dropped the valve body for an inspection of the solenoids, speed sensors, and conductor plate. Everything visually looked good. The solenoids checked out okay so far as resistance. I did this just because I had it down to this part anyway. No muck, shavings, or anything.

Reinstalled the valvebody. Installed yet another new electrical transmission connector just for good measure. This is the 2nd new one, bought it from Dodge. Installed new fluid for the 3rd time now. Used my Dorman dipstick, Torque Pro and my OBDII bluetooth transmitter to verify the transmission temp and fluid level.

Drove the car. Same issue, same code thrown. :banghead: Shift fine in rev, 1, 2, 3 and shifts into 4th fine, but after about 2-3 seconds it shifts back down to 3rd and throws the P0730 incorrect gear selected code. Doesn't matter if I leave it in D and let is shift itself or if I shift through the gears manually.

So now what? Replace the TCM? Go to the dealership and hope they don't shoot me a line of bull?
 
#20 · (Edited)
Any updates (1yr later) on resetting the TCM?

After doing the valve body overhaul, is it a MUST that I go back to the dealership to have my TCM "reset"? I would rather not. Any tips or tricks to resetting it myself? I just read thru this thread and do not see an easy way other than buying 3rd party software and hardware.

Also, I plan to unplug the negative battery terminal in the trunk today, before removing the 13-pin harness plug from the transmission. Is there an easier way to disconnect the cars power, maybe a fuse? Someone mentioned FUSE 11 would either disconnect or reset something related to the trans, I cannot remember where I read it.
 
#21 ·
Yes, mandatory, if you want to ensure the NAG1 smarts match the new operating parameters. The TCM purge / Relearn Process can only be initiated by an OBDII device.
 
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