Slow Speeds

President Camacho · Feb 13, 2017

I'm guessing this is the assembly. The connector looks like it's a big green one at the top. How do I get it off? Is it a twist?

snowtrac nome · Feb 13, 2017

your goin 45 in second likely your not feeling first shift or like all the older 4l80's I worked on they just defaulted to second and reverse. The connector you are looking for is under the drivers side rear seat, there is an aluminum water proof box that houses the tcm, that connector plugs in to the box

President Camacho · Feb 13, 2017

I only have 2 seats. It's a truck version. It'll be underneath the cab?

linhster · Feb 13, 2017

President Camacho said:
View attachment 666373I'm guessing this is the assembly. The connector looks like it's a big green one at the top. How do I get it off? Is it a twist?

That is not it! There is a compartment behind your seat (driver). Please look at the 4 man config to see where the rear seat are. It's below that.

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Wire Fox · Feb 13, 2017

President Camacho said:
I only have 2 seats. It's a truck version. It'll be underneath the cab?

If you aren't aware of them, prepare to be blown away when you discover that your 2-man truck actually has rear seats hiding underneath the truck bed filler panels. Between each front seat and the rear wheel well/sponson, you'll find that there are large metal panels that make up part of the floor (Maybe about 2.5x4 ft sized?). You can disconnect these and lift them up to reveal the passenger footwells and rear seat bases. There's a good chance that the seat cushions will be attached there, and there might just be stuff hiding in those seat bases, too. For a sense of perspective, you would be doing this all while standing in your truck bed-no need to crawl underneath to look at the TCM.

Lionel · Feb 13, 2017

Tcm connection could be loose also. Try taking off the Canon plug and putting it back.

Action · Feb 13, 2017

with an overdrive,
1st is good for up to 27 mph
2nd to 45 mph
D to 55

according to your pics, are you saying that you put the selector in ! and drive 45? Why would you do that?
Maybe the linkage is not adjusted properly and you are actually in 2nd.

Retiredwarhorses · Feb 13, 2017

erasedhammer said:
Retiredwarhorses said:

There is no kick down switch on a 4L80e equipped truck on the injector pump, or any other Hmmwv for that matter, it's a fan disconnect switch. Perform the driveabilty tests in the Troubleshooting section of the TM's.
there is a throttle position sensor on the pump that works in conjunction with the crank position sensor.[/UOTE]

24p-1 says the A0 and A1 trucks had the trans kick down. Shown below in the engine harness diagram.

View attachment 666322

Click to expand...

They do, this isn't an A0/A1 truck...TH400 is mechanical, it's uses a cable in the trans modulator.
4L80E "E"=electronic, it needs a TCM, TOSS, TPS, CPS and brake switch to unlock the TC on braking.
inside the 4L80E are shift solenoid packs....they do go bad and are easy to replace.
If you have no idea what your doing or looking at, go to a good trans shop. This is a standard GM trans.

Retiredwarhorses · Feb 13, 2017

Lionel said:
Tcm connection could be loose also. Try taking off the Canon plug and putting it back.

never unplug the TCM with the battery's connected...or ANYTHING for that matter on a hmmwv.

Retiredwarhorses · Feb 13, 2017

Wire Fox said:
If you aren't aware of them, prepare to be blown away when you discover that your 2-man truck actually has rear seats hiding underneath the truck bed filler panels. Between each front seat and the rear wheel well/sponson, you'll find that there are large metal panels that make up part of the floor (Maybe about 2.5x4 ft sized?). You can disconnect these and lift them up to reveal the passenger footwells and rear seat bases. There's a good chance that the seat cushions will be attached there, and there might just be stuff hiding in those seat bases, too. For a sense of perspective, you would be doing this all while standing in your truck bed-no need to crawl underneath to look at the TCM.

Not always...true M1037s, M1113's etc... and others never had them as they were removed for the shelters.
the TCM will just be bolted to the floor....my M1037A2 didn't have any rear seat boxes.

President Camacho · Feb 13, 2017

Thanks so much for letting me know where this thing is. I would have never had a clue where it was. I finally found the relevant info in the manual and have learned that limp will ONLY operate in 2nd. So the symptoms match! I'm happy about that at least. Hoping this is all an electrical problem! Slowly starting to understand what's happening here and get my feet underneath me. Thanks for all the help everyone.

"The recorded codes stored in the TCM are known as TROUBLE CODES which are retrieved using the Diagnostic Switch Cable on the J2 connector of the TCM. The TCM can protect the transmission from damage by locking it in Second Gear, with maximum fluid pressure, until the problem has been corrected." From: 280-20-1 2-411

Road Test is at 2-413

linhster · Feb 14, 2017

Unlike a woman (no disrespect to any ladies out there), you can and will understand the HMMWV but only with valuable time and experience. Good luck and have fun with your humvee.

Happy Valentines Day

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TOBASH · Feb 14, 2017

linhster said:
Unlike a woman (no disrespect to any ladies out there), you can and will understand the HMMWV ...

When it comes to women, it appears that you just don't have the correct technical manuals. :grin:

NormB · Feb 14, 2017

TOBASH said:
When it comes to women, it appears that you just don't have the correct technical manuals.

The words of the late Jerry Doyle come to mind here: "Remember, you're a lot happier if you're unhappy and she's happy than if she's unhappy and you're happy."

I believe the same can apply to MVs, too.

Then again, Saint Valentine wasn't writing letters to a chariot.

NB

Wire Fox · Feb 14, 2017

linhster said:
Unlike a woman (no disrespect to any ladies out there), you can and will understand the HMMWV but only with valuable time and experience. Good luck and have fun with your humvee.

Happy Valentines Day
Last contribution I have to derailing this thread...

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Last contribution I have to derailing this thread...

...now I have to say that I really like my girlfriend. She's got a few complexities, but she likes the world being straight-forward, like me. None of this saying one thing and meaning another BS. It's why I love to be around her (and she's more excited about me having a HMMWV than I am-not because she loves HMMWVs, but she knows that I love them)

3000gt · Feb 14, 2017

make sure u take advantage of that iron clad insurance!!!!!!!!!!!!!!!!!!!!

linhster · Feb 14, 2017

What does that cover (I mean from GP) ???? I was always curious.

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President Camacho · Feb 16, 2017

It's only good for 11 days. I'm way past expired. I don't trust any of these kinds of guarantees/insurance... seems like they always make it so difficult as to make it impossible to collect anyway.

Retiredwarhorses · Feb 16, 2017

President Camacho said:
It's only good for 11 days. I'm way past expired. I don't trust any of these kinds of guarantees/insurance... seems like they always make it so difficult as to make it impossible to collect anyway.

11 days after what? I have used mine on a few truck.

President Camacho · Feb 16, 2017

I thought it said it was void after 11 days after receiving the vehicle???

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