I recently did the JMOD shift kit in my 1998 mustang GT but after installing I got the O/D light flashing and it wouldn’t shift with codes. I went back in today to make sure the wiring harness was plugged in all the way but same thing happened. I believe I did everything correctly so I’m not sure how it happened. Only thing I could think of is that there is transmission fluid on the wiring harness or the plugs. Not too sure what to do from here… buy new wiring harness? Buy new valve body and wiring harness? Here are the codes after I did everything.
Transmission problems
- Thread starter Sparty443
- Start date
07GtS197
Well-Known Member
Are you sure you added enough fluid and cycled through all the positions? The 4r70w will default to 2nd gear due to it not needing either shift solenoid to be activated. It could be the internal harness is unplugged somewhere too. Improper installation or loose bolts could all cause these issues as well. If it’s not the fluid, drop the pan and recheck the torque on the valve body bolts.
Wmac
Active Member
Agree with the above. Add fluid a couple of quarts at a time with engine running. Cycle shifter through each position with a pause of a second or 2 at a time. You will not actually feel it go into gear until the trans is about half full. Always measure the amount of fluid that is removed.
All of the codes shown above are for manual trans, so clear these codes.
All of the codes shown above are for manual trans, so clear these codes.
I went on today torqued all the valve body bolts, added enough fluid, cleared the codes and still doing the same thing. It goes into reverse and drive but it dose not want to shift. No clue what to do now. Order new valve body and wiring harness?
Not sure what to do now still having problems after going in and torquing the valve body bolts and adding enough fluid. Maybe buy new valve body or all new sensors and wiring harness
Wmac
Active Member
Will the shift lever go into every gear? From 1st up to park?
Yea it will
Wmac
Active Member
Ok, so the manual valve detent lever is installed correctly on the v/b and will allow all positions on the shifter to be selected, is the mlps "'lined-up" correctly?
Are all the check balls installed in their original location as well as the small filter/ screen?
You mention above that it will go into reverse and actually move backwards?
And will go into drive but not shift? Will it move forward?
Can you drive the car forward and manually shift 1/2, 2/3?
Are all the check balls installed in their original location as well as the small filter/ screen?
You mention above that it will go into reverse and actually move backwards?
And will go into drive but not shift? Will it move forward?
Can you drive the car forward and manually shift 1/2, 2/3?
The car would move into reverse and move forward but would not go past 30 mph. I’m almost positive I put all the check balls and screen and filter all in the right location. Haven’t tried manually shifting it yet,
07GtS197
Well-Known Member
Good catch about the mlps. It could be misaligned. Op check the mlps, or as it’s also known as the neutral safely switch. There are two lines that need to be lined up when it’s in neutral or else you’ll have all sorts of issues. Otherwise, there’s no power to the shift solenoids for whatever reason. Have you checked all your fuses?
