Engine swap went well. All is put together and runs beautifully. I took her out for a test drive and the speedometer does not read and she will not shift out of limp mode.
These worked fine before the 6.5TD to 6.5TD swap.
Research told me to remove the output sensor on the transfer case and clean it. Did that, but problems persist. Fluid level is good and, as far as I can tell, everything is plugged in, etc.
Any ideas? Else she's going to the transmission shop at the end of the week.
-Thanks!

 

Thoughts... anyone???

 

Pm hummech here on the forum. he can walk you through the various potential causes for you being in limp mode and how to check each of them.

 

make sure that you plugged in the digital ratio adapter? that runs the speedometer and gives the speed signal to the PCM. you may have unplugged it when you removed the inner engine cover.

 

I found this explanation on-line for the H2. I hope it helps someone else, I know it sure saved my b u t t.

I can’t get the H2 out of park!

Park Problem – emergency procedure

This is a more serious problem as the truck is totally immobilized. You will have to do something if you want to get to where you are going. Fortunately, the solution is very easy. Note that The park problem can occur at the same time as the key problem so you may have to do both to get out of a bind . The repair of the shifter as described below will fix both problems.

Here's what you do.

Open the center console glove box and using the Phillips screw driver, remove the 4 screws that hold the center console "glove box" in place. The box is the tub right under the flip up door. (See picture 1 below)


Center console Remove the tub then stick you hand into the hole toward the shifter. While jiggling the shifter feel where the bottom of the shifter is. Somewhere near the bottom, you will feel a round mushroom shaped thing, with the round part facing the PASSENGER SIDE. If you press on this, the shifter can now be shifted out of park using the regular method. You need to hold the button down when you want to shift out of park. The lock is only for park so all other gears are ok from this point on. Remember- every time you go to park position, the shifter will lock and you need to access the “button” each time to get out of park. (See picture 2 below)


What causes the problem?

One frequent cause is a broken wire that goes to the shifter (the break is located in the center console). These wires control both the key removal and the parking lock. If you have either of these problems then have the cable checked or you can fix it your self as indicated below:

Put the parking brake on

Make sure the engine is off

Put the shifter into 1 (farthest back position)

Remove the shifter handle. To do this you need to loosen the torx screw (it is actually a torx screw but an allan wrench works. (See picture 3 below)



Loosen the screw on the front of the shifter.

Pop the shifter console off the center console. There are 4 very hard to release metal clips that hold the shifter cover on. To release, you need to pull straight up on the shifter cover. Beware, you might break the plastic around the clips so be careful. The cover does come off with a lot of effort. If you are worried about breaking it go to a dealer for the repair.



Once the cover is off you will see a cable and connector near a mushroom shaped button. This button is the one you pressed to release the shifter from park. Either the connector is off or the wires to the connector are broken due to the flex back and forth that occurs during movement of the shift lever. (See picture 4 & 5 below)



Find which wire is broken and fix it. It is preferable to use a small gauge, highly flexible wire to extend the harness to connector cable length. It is also preferable to use butt splices rather then solder joints.

Test it and then put everything back together.

pic 1, pic 2, pic 3, pic 4, pic 5

See pics on my mocart4u post

 

I am trying to figure out why my HMMWV keeps going into limp mode every time is gets under any kind of load as in quick acceleration or going up a him. If I baby it and go slow and be very disciplined I can operate it for a period of time such as 15 or 20 mins. It isn’t going to blow up or anything but it doesn’t run right and I can’t go more than 45 or 50 minutes before it will drop down and going to the limp mode. Does that ring any bells for anybody. Because this has been going on for about 5 months and been to 3 different shops and no one can figure out what it is. Please help!!

 

did you replace tranny? There's two sensor locations on the the 4l80 trans that the hummers use both for shifting. I had swapped a tranny out amd was missing reluctor ring in the one location and it wouldnt shift

 

who is the guy that can walk me through the limp mode situation. I have a vehicle M1027
Had it for two years. A year of that it’s been stuck in limp mode. I have tried everything. Who can help me walk through the limp modes and figure out what in god’s name is causing this. I’m about to **** on it and set it a fire.