I tow my 2008 H3 behind a motorhome. I'm on the road and can't get the transfer case to shift back into 4 high. I put it in neutral when we left, but when I got back in it to drive off, NO lights indicating which mode it is in where on. The neutral N isn't on any more. And the "serv 4wd" comes on. Won't shift into 4high either. The lights will come on and start blinking when it tries to shift the transfer case, but then nothing happens and it gives up. It also starts blinking warnings about traction and something else.

It was a very rainy, wet drive. I'm pretty convinced that it must be electrical, since it doesn't even know if it is in gear or not. I checked all of the fuses that I could think of, and all is good. I also went underneath and checked and shook all the wires to the transfer case. ANY help would be greatly appreciate. Thanks.

 

You tow it behind your motor home?

Are you using a tow bar or dolly? Leaving the wheels on the ground?

If so,, you've likely blown your transfer case. The H3 is a full time 4x4 so if you are using a dolly leaving the rear wheels on the ground without disconnecting the rear drive shaft your T-case is done.

Same difference if you're towing it over long distances in neutral with all 4 wheels on the ground.

 

[QUOTE=Smittro;285375]You tow it behind your motor home?

Are you using a tow bar or dolly? Leaving the wheels on the ground?

If so,, you've likely blown your transfer case. The H3 is a full time 4x4 so if you are using a dolly leaving the rear wheels on the ground without disconnecting the rear drive shaft your T-case is done.

Same difference if you're towing it over long distances in neutral with all 4 wheels on the ground.[/QUOTE

Read your owner's manual. The NEUTRAL position he refers to is for the TRANSFER CASE. This function is for towing with all 4 wheels on the ground. He did everything right. I suspect the water spray has gotten somethin wet and things will work correctly after it dries out. A battery disconnect may ne in order.

 

[QUOTE=RKSmith163;285382]Read your owners manual, the H3 can ford 24 inches of water. If something got wet just pulling it level then there's a bigger issue at hand.

It's well known throughout the automotive industry that towing ANY automatic over long distances in Neutral is not good for it..

 

Kingpenm3, Did you get the transfer case to go back into gear now that everything has dried out? BTW, how many miles have you put on the RV towing the H3? Just curious.

 

[QUOTE=Smittro;285414]


RESPONSE
Hours of high velocity spray will penetrate electrical componants much deeper than a quick dip in 24" of standing water.

From the 2007 Owners Manual

N (NEUTRAL): Shift the vehicle’s transfer case
to NEUTRAL only when towing your vehicle.
See Recreational Vehicle Towing on page 295
or Towing Your Vehicle on page 294 for more
information.

Recreational Vehicle Towing

Recreational vehicle towing means towing your
vehicle behind another vehicle — such as behind
a motorhome. The two most common types of
recreational vehicle towing are known as “dinghy
towing” (towing your vehicle with all four wheels
on the ground) and “dolly towing” (towing
your vehicle with two wheels on the ground and
two wheels up on a device known as a “dolly”).
With the proper preparation and equipment,
many vehicles can be towed in these ways. See
“Dinghy Towing” and “Dolly Towing,” following.
Here are some important things to consider before
you do recreational vehicle towing:

• What’s the towing capacity of the towing
vehicle? Be sure you read the tow vehicle
manufacturer’s recommendations.

• How far will you tow? Some vehicles have
restrictions on how far and how long they
can tow.

• Do you have the proper towing equipment?
See your dealer or trailering professional
for additional advice and equipment
recommendations.

• Is your vehicle ready to be towed? Just as
you would prepare your vehicle for a long
trip, you’ll want to make sure your vehicle is
prepared to be towed. See Before Leaving
on a Long Long Trip on page 278.

Dinghy Towing

Use the following procedure to tow your vehicle:

1. Shift the transmission to NEUTRAL (N).

2. Turn the engine off, but leave the
ignition in ON.

3. Firmly set the parking brake.

4. Securely attach the vehicle being towed to
the tow vehicle.

{CAUTION:
Shifting a full-time four-wheel-drive
vehicle’s transfer case into NEUTRAL
can cause your vehicle to roll even if the
automatic transmission is in PARK (P) or
the manual transmission is in any gear.
You or others could be injured. Make sure
the parking brake is firmly set before
you shift the transfer case to NEUTRAL.

5. Shift the transfer case to NEUTRAL (N). See
Full-Time Four-Wheel Drive on page 111 for
the proper procedure to select the NEUTRAL
position for your vehicle.

6. Put the transmission in PARK (P) for an
automatic transmission or in FIRST (1) for
a manual transmission.

7. Release the parking brake only after the
vehicle being towed is firmly attached to
the towing vehicle.

8. Turn the ignition off.
After towing, see “Shifting Out of NEUTRAL”
under Full-Time Four-Wheel Drive on page 111.

Dolly Towing

Notice: Dolly towing your vehicle will damage
drivetrain components. Do not dolly tow
your vehicle.
Your vehicle cannot be dolly towed. If you must
tow your vehicle behind another, use the
dinghy towing procedure listed previously.

 

I guess you better not drive it in the rain then huh?

Weather pack connectors are designed to be water tight.

Water penetration to electrical componets would effect the power train control module more than just a service light.

Did you have the vehicle scanned for codes? If so what codes were logged by the PCM??

The rest of the post pretty much confirms what I stated..

These things are'nt from some kid pulling crap out of the air.

It comes from years (more than 20) of working in various automotive fields from passenger cars to heavy road use vehicles and automotive electrical systems.

As well as engine and drive train performance and overhauling builds.

My posts stand.

 

No, I never got it going again. It stayed wet and rainy all weekend, not very good conditions for something to dry out. And as far as something getting wet, it could have been from the inside. We have had two experiences where we got a good bit of rain water INSIDE of the vehicle during heavy rain.

The good news was that since I had the motorhome, i didn't have to get it towed, I just hooked back up and took it to the dealership. If I had to guess, I'd say about 6k miles of tow time. I don't see many h3's being used as "toads", but it maybe the easiest vehicle to tow out there. No fuse pulls required, doesn't count mileage, battery doesn't run down while being pulled. Great tow vehicle.

 

Thank you for the update. I hope it's a quick, easy and inexpensive fix.

 

Well, it's been right at one month since I had the breakdown and I finally got the hummer back yesterday. Here's what happened:

Took it back to the dealership that I bought the truck from (non-GM, bought it used). They said it was over their head and to take it to a GM dealership.

Had it towed from there, but the company that towed it (that also is a car shop) said they could fix it, they wasted their time diagnosing it because the repair ended up falling under the 100k mile powertrain factory warranty. So they towed it to a GM dealership.

They agreed with the diagnosis from the first shop, that the actuator that switched the transfer case was defective. Ordered parts, installed parts, still no fix.

Then they opened up the transfer case to see what was going on internally, to find that the plastic fork was broken. Replaced it and I'm finally good to go again.

Funny part is that when I was googling for info from the start, a broken factory plastic fork was what came up the most often.

Best part is, all of this didn't cost me a dime. Factory powertrain warranty took care of all of the repairs, and insurance even picked up the tow charge.