In need of some diagnostic help

[trebor]

My wife, who drives the hummer about 3 miles to work each day, mentioned to me that it seemed like the brakes were dragging in the parking lot at her work. I just went with at test drive with her to see if we could reproduce the issue. It seems that part of what she felt was when she was parking she had to back up, so she shifted into reverse and hit the accelerator and the engine seemed to stall or shudder a little. Well to make a long story a little shorter, I was able to duplicate this every time I came to a stop and put the trans in reverse the engine seemed to either miss or stall out for about a full second, then seemed to accelerate just fine. When backing out of my garage I do not feel anything, just after the trans was in a forward gear first and then shifted into reverse.

Any ideas what this could be?

It has 2700 miles on it and I have already made an appointment with the closest dealer which is about 120 miles away to service it and also check to see why none of the dash lights dim when you adjust the rheostat.

[trebor]

My wife, who drives the hummer about 3 miles to work each day, mentioned to me that it seemed like the brakes were dragging in the parking lot at her work. I just went with at test drive with her to see if we could reproduce the issue. It seems that part of what she felt was when she was parking she had to back up, so she shifted into reverse and hit the accelerator and the engine seemed to stall or shudder a little. Well to make a long story a little shorter, I was able to duplicate this every time I came to a stop and put the trans in reverse the engine seemed to either miss or stall out for about a full second, then seemed to accelerate just fine. When backing out of my garage I do not feel anything, just after the trans was in a forward gear first and then shifted into reverse.

Any ideas what this could be?

It has 2700 miles on it and I have already made an appointment with the closest dealer which is about 120 miles away to service it and also check to see why none of the dash lights dim when you adjust the rheostat.

[wannabeH3]

just take it to the dealer and have it checked out

[fourfourto]

Hit the onstar button have them run a check it couldnt hurt.
The best things in life are free(at least for 1 year)


H3 gray adventure ,sunroof, steps ,roof rack ,smokers package ,window vents, sunroof visor, hard spare tire cover, h3 valve caps ,mudflaps and K&N filter 3,000+ miles

[Jake]

i beleive this is a factory setting let the vehicle come to a complete stop then put in reverse and hit the accelerator

[f5fstop]

From what you describe, and not being there to actually test it myself, I believe Jake has it right.
Years ago, GM and other manufacurers started programmed a delay into the shift from a forward drive gear to reverse and vice versa. Too many people were rocking their cars and not allowing the engine speed to reduce to idle before the shift. This caused some heavy warranty costs, especially in the winter months.

I know mine has that same feeling, so when I go from drive to reverse I come to a complete stop, engage reverse (foot still on the brake), the start to back up and then I do not have the built in delay.

[Hummertech]

Jake is correct. They are designed to purposefully misfire if it is put in reverse before it is at a complete stop.

[TexasRTR78]

...but what about the brakes dragging part??...I, too, have felt this in my H3..not very often but it does seem like the brakes drag sometimes when going very slow..like through a parkling lot.

[1COOLH3]

Here is the Bulletin- it is a normal condition to protect the transmission:

Engine Miss on Acceleration After Shifting from Drive to Reverse - Possible Characteristic - keywords 1 abuse accel accelerate cut cutoff cylinder fuel hesitate hesitation in management misfire normal #PIP3485 - (Jul 1, 2005)
Engine Miss on Acceleration After Shifting From Drive to Reverse - Possible Characteristic
2005-2006 Chevrolet Colorado

2005-2006 GMC Canyon

2006 Hummer H3

with an Automatic Transmission

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
A brief engine miss may be experienced if the transmission is shifted from drive to reverse and then accelerated when the vehicle is still moving in a forward direction. If monitored with a Tech 2, it may be noted that a few engine misfires are present on cylinder 1 during the concern. It may also be noted that other vehicles in new car inventory exhibit the same concern. This is the result of a torque limiting feature to prevent transmission damage.

Also a lot people with the "dragging brakes" are actually feeling the All Wheel Drive operation. It's the same feeling as driving a truck in 4 wheel drive on dry pavement.

[trebor]

The issue is that I am coming to a complete stop, it is breif but it is a complete stop. It also does it on the second and third time that you hit the accelarator after you are already in reverse.

I am an ASE Certified Mechanic so I now the damage that can be caused from shifting from drive to reverse without stopping. I have not felt this in the first 2500 miles. I back out of my garage at least 5 times on Saturdays alone and have never felt it until now.

As for the brake drag, I have not felt it or been able to duplicate any other symptoms.

As my wife says, just like when I had my own shop, the vehicle never acts up when you take it to the mechanic.

I will be taking it into the dealer as I said, but being a mechanic that has worked for GM, Ford and myself, I like to know as much as I can about the problem before I take it in. I have known many service writers that bullsh*t the owner so much that I have lost faith in most service writers. I don't know this dealer and I was not able to buy my H3 from them because of inventory problems at the time (they could not get any one to trade stock with them).

[f5fstop]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by trebor:
I will be taking it into the dealer as I said, but being a mechanic that has worked for GM, Ford and myself, I like to know as much as I can about the problem before I take it in. I have known many service writers that bullsh*t the owner so much that I have lost faith in most service writers. I don't know this dealer and I was not able to buy my H3 from them because of inventory problems at the time (they could not get any one to trade stock with them). </div></BLOCKQUOTE>
Then being an ASE certified mechanic, let the ones trained on the Hummer H3, work on it and see if there is a problem.
I in fact know that this is programmed into the TCM and PCM, and the conditions you state make it sound like it is the program.
(PS I'm not BS'ing you, and I'm not a service writer at a dealership; even if that sometimes sounds like it would be less stress than working at GM. )

[trebor]

Hey f5fstop, I am not saying I don't believe that it is in the program. And I already said I was going to let them check it.

Dang I can't even ask a question, what the HELL!

I think if it was your vehicle you would do as much research on the issue you could before taking it in and wasting someone's time if it was normal. Which with the posts here says it is only normal for a rolling gear change.

Heck all I was doing was stating that I feel like it is doing it all the time not just when you are doing a rolling gear change.

Anyway, I went and picked it up from my wife's work and tested it again to make sure that I was coming to a complete stop - I was. I also went from reverse to drive and felt the same thing, retested it to make sure I made a complete stop - I was.

If you don't think a program on a computer can mess up, I have a copy of WindowsME that I will sell you!

[CTH3]

Let us know if they offer a solution, mine does the same thing in forward and reverse. It does seem strange that you never noticed it until now though. Good luck.

[Sharkster]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by trebor:
It has 2700 miles on it and I have already made an appointment with the closest dealer which is about 120 miles away to service it. </div></BLOCKQUOTE>My next HUMMER dealer is around 9,000 miles away...

[trebor]

Hey f5fstop, do you really work for GM?

Turns out it is the transmission, they ordered a new one and gave us a loaner till they get it replaced. GM says they have to ship this one back for tear down for quality control.

I hate people who just think they know everything and then turn out to not know what the hell they are talking about.

[trebor]

Oh yeah, they also told us they felt so bad about us having problems that they would drive the 120 miles each way to bring it back to us and pick up their loaner. They did not even sell it to us, we had to go to another dealer because they could not get what we wanted unless we ordered.

[TexasRTR78]

Trebor, I hope you are talking about Soggin-Dickey...that's where my husband bought mine...they treated us like gold. If you are talking about them, I am glad to see that they treated you so well! It only reassures me that if something ever goes wrong with mine that they will do their best to fix the problem and treat us good at the same time!

I am glad that your H3 ailment is being fixed ...please keep us posted to see how things go!

[trebor]

We got the Hummer back last night, they delivered it to us. All the issues with the shudder are fixed. The transmission works perfect.

Only problem is they failed to fix the dash lights, so they would dim. I think they just got tied up on the trans, but I am disappointed that I will have to take it back. The service writer at Scoggin-Dickey has offered to come and pick it up to fix it though. I will let ya'll know if it ever gets fixed.