Transmission DTCs and Problems

jbaskin28

New member
So, I have an issue I need help with ASAP.

Jeep was giving issues with starting a while back and figured out it was the Transmission Range Sensor. Today, my buddy and I decided to try and replace it, and should have been a fairly quick process. However, the process became long, and after unable to get the valve body out to replace the part, I said screw, and we put her back together. I poured in 6 quarts of Valvoline ATF +4 and started her up (was weird because she cranks on every attempt now, intermittent start issue is gone). I cycled through the gears and back in to park.

NOW I have an even LARGER issue. I can put her in to reverse just fine and go (backwards). If I drop her in to Drive, she does nothing. I can press the gas and at around 2000 RPMs, she lurches forward a little bit, but it feels like something is locked up, because if I hold down the gas or give her more and try to go, it shutters and moves very slowly forward.

I ran the diagnostics from my Bully Dog Tuner, and got the following

P1790 - Unkown DTC
P0731 - Gear 1 Incorrect Ratio
P0841 - Transmission Fluid Pressure/Sensor A Circuit Range/Performance

I have scoured the internet trying to find the answer, but can't seem to come up with one at all. I would like to know if I can fix it myself, or need to take it in. And if the later, a rough estimate of how much it would cost (best to worst case scenarios).

Thanks for the help!!!

Oh, I should add, though I feel I may not need to, BUT, it is an Automatic. 2008 JK.

Addition: After trying to go forward and I stop, I can smell a burning smell.
 
Last edited:

hydrohut

New member
So, I have an issue I need help with ASAP.

Jeep was giving issues with starting a while back and figured out it was the Transmission Range Sensor. Today, my buddy and I decided to try and replace it, and should have been a fairly quick process. However, the process became long, and after unable to get the valve body out to replace the part, I said screw, and we put her back together. I poured in 6 quarts of Valvoline ATF +4 and started her up (was weird because she cranks on every attempt now, intermittent start issue is gone). I cycled through the gears and back in to park.

NOW I have an even LARGER issue. I can put her in to reverse just fine and go (backwards). If I drop her in to Drive, she does nothing. I can press the gas and at around 2000 RPMs, she lurches forward a little bit, but it feels like something is locked up, because if I hold down the gas or give her more and try to go, it shutters and moves very slowly forward.

I ran the diagnostics from my Bully Dog Tuner, and got the following

P1790 - Unkown DTC
P0731 - Gear 1 Incorrect Ratio
P0841 - Transmission Fluid Pressure/Sensor A Circuit Range/Performance

I have scoured the internet trying to find the answer, but can't seem to come up with one at all. I would like to know if I can fix it myself, or need to take it in. And if the later, a rough estimate of how much it would cost (best to worst case scenarios).

Thanks for the help!!!

Oh, I should add, though I feel I may not need to, BUT, it is an Automatic. 2008 JK.

Addition: After trying to go forward and I stop, I can smell a burning smell.

Is the trans reading full on the dip stick, just wonder if you are still too low on trans oil. If not that, I would guess maybe something has not gone back together as it should of in that valve body. How far apart did you get it? Lots to go wrong there if you are not sure what you are doing.
 

jbaskin28

New member
Trans dip stick reads full. We didn't get the valve body out. Got fed up trying to get it out and didn't realize the shifter linkage was still holding the rod in place and would let the valve body come out. So we bolt it all back up.
 

hydrohut

New member
Trans dip stick reads full. We didn't get the valve body out. Got fed up trying to get it out and didn't realize the shifter linkage was still holding the rod in place and would let the valve body come out. So we bolt it all back up.

Seems like you or someone else will have to go back inside it and recheck for something misplaced in there. If you had the valve body loose I suspect something may have fallen out of alignment between the valve body and trans housing? Have you plugged everything electrical back in? and not bent any plug pins in the process? I wouldn't advise even trying to drive it forward or backward until you have had another look inside. Burning smells are not good.
 

jbaskin28

New member
Seems like you or someone else will have to go back inside it and recheck for something misplaced in there. If you had the valve body loose I suspect something may have fallen out of alignment between the valve body and trans housing? Have you plugged everything electrical back in? and not bent any plug pins in the process? I wouldn't advise even trying to drive it forward or backward until you have had another look inside. Burning smells are not good.

My buddy did that today form me. Was missing a check ball and a plate that slipped out of the work hole on the valve body. He found a guy that gave him three check balls. Put the one and the plate in and presto change, she drives again!! So stoked!
 

hydrohut

New member
My buddy did that today form me. Was missing a check ball and a plate that slipped out of the work hole on the valve body. He found a guy that gave him three check balls. Put the one and the plate in and presto change, she drives again!! So stoked!
That's excellent news!
 
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