Project Thor HMMWV - Electrical & Transmission

[@arubisx]

Brother. Listen. I had my trans "stuck" in second for a year. It was the TPS. I don't know if the TPS is bad or not, but I did something one day that made a world of difference. I just unplugged the TPS sensor and took the truck for a drive. It fucking started shifting!!! I was so happy. Anyway now I know the issue lies with the TPS, the only issue is I'm not sure if the sensor just needs to be calibrated or replaced. But for now, I'm just driving it with the sensor unplugged. Please let me know if this works for you. Good luck!

[@terrafusiontx]

That's good advice. I have two problems though. My injection pump sticks while accelerating AND is stuck in limp mode. So right now I'm pulling the pump. Actually did some work this morning on it. Video coming soon. :)

[@thannaas]

How does the the transmission know how to shift when the TPS is disconnected? Is it only for the kickdown shifting?

[@jonathanbetancourt3910]

Where did you get the information revolving steps for different error codes ? Is it just included with the vehicle having the same issue here and I see the diagram you have is helpful but I’m using only schematics and don’t have that flow chart

[@terrafusiontx]

I have the 4l80 troubleshooting guide

[@terrafusiontx]

drive.google.com/drive/folders/1Im_0c8ZNuadpd0pLc7uYtQaKzo4Ay20t

[@angrypatriot5392]

Man, I'm tellin' ya. They left the trucks in Afghanistan in better condition than what they auction off to the public here in the United States. Smh

[@terrafusiontx]

Hah! Seriously

[@jimbutler6391]

The transmission control module says right on it not to disconnect with the battery connected. Did you do your J1 checks with the battery disconnected or what?

[@terrafusiontx]

It's been a hot minute since I did this but I followed the TM for troubleshooting the transmission. I do remember disconnecting everything.

[@jimbutler6391]

@@terrafusiontx Thanks. For anyone else doing this I disconnected the battery, disconnected the J1 connector, then reconnected the battery (with the J1 still disconnected) to start the truck for further tests as directed by the technical manual. The manual never really explains that procedure.

[@mikeshaw7670]

on the diagram for the pins the upper half has upper case and the lower half has lower case the diagram shows as an example pin D and pin f just pay attention to that

[@terrafusiontx]

Seriously. Pay attention to this. I got twisted arounda few times on it.

[@MiamiGeneralContractor]

My 99 1097 humvee was working fine now is tripping the red breaker by the passenger side. Ao frustrating don't have any codes but i cant figure out the problem

[@terrafusiontx]

Check your ground

[@MiamiGeneralContractor]

@@terrafusiontx which one?

[@terrafusiontx]

Take that back. The breaker could be bad. No codes is a a good indicator of that.

[@MiamiGeneralContractor]

@@terrafusiontx ill try another breaker and see.

[@terrafusiontx]

Did that work out?

[@thannaas]

Did you get any fault codes flashing for you in the trans bulb?

[@terrafusiontx]

Just 1 - 2 over and over. It was weird.

[@thannaas]

@@terrafusiontx Any trouble with the TPS or did you measure it?

[@terrafusiontx]

@@thannaas I got a failed test on the TPS itself when i did the test. The whole side the TPS was on was sticking to. So i ended up ordering new IP and TPS. The other failed test was the engine RPM sensor.

[@thannaas]

@@terrafusiontx How did you test the TPS? Measuring the volts? Does the RPM sensor from the engine work with the transmission? I thought it was just for the STE/ICE troubleshooting system?

[@terrafusiontx]

I followed the 4L80E troubleshooting guide. The TPS requires a specific adapter to effectively test it. Black Dog Customs makes an aftermarket adapter. However, i managed to at least confirm a resistance test through the sensor. The engine rpm sensor is used for the transmission and has steps to test it in the guide. Here's a link to the guide. drive.google.com/file/d/1AGKR6E0vreqOW-2GwPsFf6vGc0GJX6VQ/view?usp=share_link