Haven't seen yall in awhile. Sorry to hear you're having trouble with your hmmwv. Firstly the kick-down switch does down shift the transmission, it also tells the time delay module to disengage the fan when you mash the accelerator real quick and turn off the a/c if installed by manual to specs. I would check the tps first, there should be three wires. 1 is the 5volt reference, 2 is the signal wire, and the 3rd is the ground. Next i would check the circuit breaker to see if it is getting power, in and out. Sometimes there is a fusible link hidden in there. If all that checks out, check for power at the tcm. If you have power then see if you can pull codes. On my hmmwv i jump pins a and e, you watch the trans light and count the flashes. Most people do this with a paperclip. 12 will be the first and last code. Oh one more thing, make sure your trans connector isn't flooded with fluid. Hope this helps you some.
@@mattlawson7007 Thank you so much for all the info! I will start checking all those parts you mentioned! I need to do some research and find out where all of those are located first LOL 🤣 I will probably post another video soon about the process of finding the problem. I really want people to be able to use these videos so it would help them to solve similar problems if they encounter them! Again, thank you so much for your help 🙏
You're welcome. The tps is located on the side of the injector pump opposite of the throttle cable. The tcm is under the rear driver side seat. Just be careful with the tcm, most folks forget they are a 12volt system not 24volt like the rest of the hmmwv. If yours has it unscrew the cap and you'll find the pins labeled, right beside the one with the harness. By the way, you're doing good, all of us that have hmmwv's have had to figure out one thing or another.
I had the same issue took me months to find the problem, I was on the verge of of rebuilding the transmission and installing a stand alone TCU. Turns out it was a bad speed sensor and a bad TPS. $200 for both. I saved $2k
You should check if the Circuit Breaker tripped located behind the Passenger side seat. It would cause it to go into limp mode. Another culprit could be a bad TCM. Definitely should do the paperclip trick to see what codes pop up.
Thank you so much for the reply! I checked the circuit breaker behind the passenger seat and it looks like it did not trip. What is the paper clip trick? I am curious to learn :-)
Haven't seen yall in awhile. Sorry to hear you're having trouble with your hmmwv. Firstly the kick-down switch does down shift the transmission, it also tells the time delay module to disengage the fan when you mash the accelerator real quick and turn off the a/c if installed by manual to specs. I would check the tps first, there should be three wires. 1 is the 5volt reference, 2 is the signal wire, and the 3rd is the ground. Next i would check the circuit breaker to see if it is getting power, in and out. Sometimes there is a fusible link hidden in there. If all that checks out, check for power at the tcm. If you have power then see if you can pull codes. On my hmmwv i jump pins a and e, you watch the trans light and count the flashes. Most people do this with a paperclip. 12 will be the first and last code. Oh one more thing, make sure your trans connector isn't flooded with fluid. Hope this helps you some.
@@mattlawson7007 Thank you so much for all the info! I will start checking all those parts you mentioned! I need to do some research and find out where all of those are located first LOL 🤣
I will probably post another video soon about the process of finding the problem. I really want people to be able to use these videos so it would help them to solve similar problems if they encounter them! Again, thank you so much for your help 🙏
You're welcome. The tps is located on the side of the injector pump opposite of the throttle cable. The tcm is under the rear driver side seat. Just be careful with the tcm, most folks forget they are a 12volt system not 24volt like the rest of the hmmwv. If yours has it unscrew the cap and you'll find the pins labeled, right beside the one with the harness. By the way, you're doing good, all of us that have hmmwv's have had to figure out one thing or another.
@@mattlawson7007 I will start the troubleshooting! Again, thank you so much Matt!
I had the same issue took me months to find the problem, I was on the verge of of rebuilding the transmission and installing a stand alone TCU. Turns out it was a bad speed sensor and a bad TPS. $200 for both. I saved $2k
Thank you so much for the reply :)
Wow! That is crazy!
I am so happy you solved it in just replacing those two.
How did you figured it out
You should check if the Circuit Breaker tripped located behind the Passenger side seat. It would cause it to go into limp mode. Another culprit could be a bad TCM. Definitely should do the paperclip trick to see what codes pop up.
Thank you so much for the reply! I checked the circuit breaker behind the passenger seat and it looks like it did not trip. What is the paper clip trick? I am curious to learn :-)
I need to change that on my Humvee too. Great video man keep it up.
Thank you so much! It's a pretty easy change 😁
Here it is, good luck.