Bulletin No.: 24-NA-029

Service Bulletin

Date: July, 2024

INFORMATION
Subject:

Brand:

GMC

HUMMER EV Water Leak Diagnostic Tips

Model:

Model Year:
from

to

HUMMER EV Pickup

2022

2025

HUMMER EV SUV

2024

2025

Important: Service agents must comply with all
International, Federal, State, Provincial, and/or
Local laws applicable to the activities it performs
under this bulletin, including but not limited to
handling, deploying, preparing, classifying,
packaging, marking, labeling, and shipping
dangerous goods. In the event of a conflict
between the procedures set forth in this bulletin
and the laws that apply to your dealership, you
must follow those applicable laws.
Important: This technical service bulletin (TSB) can
only be completed by certified repair facilities who have
met all specific training, tool and equipment requirements pertaining to the vehicle Brand and Model
serviced. Repairs must be performed by a technician
who has successfully completed the required training.

General Information
Water leaks can occur due to a variety of reasons.
Success to finding the source of the leak starts with
duplicating the leak or acquiring pictures or videos of
the leak from the customer.
Step 1 in any water leak diagnosis begins with understanding where the leak is coming from and under what
conditions it occurs. How quickly does the leak
appear once the rain starts? Does it leak during a light
rain or downpour? Does it happen while going through
an automatic car wash with high-speed blowers? Is the
leak constant or intermittent?

Copyright 2024 General Motors. All Rights Reserved.

VIN:
from

to

-

-

Engine:

Transmission:

All

All

Another common cause of a leak is from the use of a
high-pressure power washer. The sealing capability of
frame-less side glass design of the vehicle is easily
overcome with the use of a high power-pressure
washer being sprayed directly onto the edges of the
side glass where the glass meets the door opening
weather strips. Refer to the Owner’s Manual for
additional Exterior Care information.
Knowing the conditions that cause the leak plus an
understanding of where the leak appears is key to
resolving the customers concern. The purpose of this
bulletin to help guide you through proper diagnosis as
well as provide some actual causes of leaks and what
action was taken to repair the leak.

The following information is split into 3 categories.
1. I-Bar Water Leaks
2. Sky Panel Water Leaks
3. Side Window Water Leaks

I-Bar Water Leaks

Page 2

July, 2024

Bulletin No.: 24-NA-029

Model Year 2022 only
Model Year 2022 — Current

6541873

This design is from 2022 ONLY. If the open cell foam is
discovered, check the vehicle for open field action and
replace the I-Bar per Service Update Bulletin
N222378440.
Condition

6542034

Water pours out of the lower I Bar trim cover as it collects in the sump created by the
contour of the trim, especially when turning a corner.

Easiest way to diagnose this complaint is to remove the
lower trim panel, water test, and watch for the leak.

6542125

6542118

With trim panel removed, if water is leaking through the
I-Bar as shown, replace the I bar.

The front I Bar is designed to be removed by the
customer. If the front I bar is installed backward it will
leak. When removing the I Bar, inspect the orientation
of the I Bar to ensure the “front” is in fact pointing
towards the front of the vehicle. Inform the customer on
proper installation if this condition is found.

Bulletin No.: 24-NA-029

July, 2024

Page 3

Another possible cause of water droplets in this area
can be caused by creased I Bar weather strips.

6542146

Water leaking near the front or rear of the I Bar in this
zone is usually not caused by the I Bar. Water droplets
coming past the weather strip and roof headliner panel
are due to excessive water building up in the drain
system. If any sky panel is out of alignment, excessive
water can get past the sealing surfaces and allow too
much water to enter into the drain system, thus
allowing water to exist in unwanted locations. Inspect
the sky panels for proper alignment and adjust as
necessary. Refer to SI DOC ID 6339878 (pickup) or
6341146 (SUV).

6542173

6542199

Page 4

July, 2024

Bulletin No.: 24-NA-029

Cause

Folded over weather strips on the I-Bar due to improper sky panel installation. Pay close
attention to these areas when first removing the sky panel. If the outboard weather strip
ends are folded over this will cause the sky panel to raise up preventing a good seal. If
the crease is permanently set as shown below, this will also prevent the weather strip laying flat even with the sky panel installed pushing the sky panel upwards causing a gap
and leak.

Correction

Replace the I-Bar – educate customer on proper sky panel installation.

The recessed areas where the I Bar mounts to the roof
are part of the water management system and
designed to be wet.

Carefully place the roof panel into its designated
location. Position the inboard edge of the roof panel
next to the weatherstrip on the I-Bar, then align and fit
the horizontal pins into the receivers on the I-Bar.
When aligning the pins and receivers, make sure the
inboard edge of the roof panel does not come in
contact with the roof seals. Ensure that the inboard
edge is far enough in that it clears the I-Bar weatherstrip. Ensure that the I-Bar weatherstrip is lying flush
with the adjacent roof seals before fully engaging the
pins into the receivers. Failure to do so may damage
the weatherstrip or lead to an improper seal.

Sky Panel Water Leaks

6543780

It is normal to have presence of water as shown.

Proper Sky Panel Installation per Owners Manual

6542230

Bulletin No.: 24-NA-029

July, 2024

Page 5

Condition

Leaks near the top of any of the side windows, weather strips, or sky panel weather strip.

Cause

If any sky panel is out of alignment such as being shifted too far forward or rearward, or
too high, this will causing excessive water to enter into the water management system in
the weather strips. This causes water to back up over the sealing surfaces creating a
leak inside the cabin near the corners of weather strips near the weather strip drain
holes.

Correction

Perform top down, side to side, visual inspection of all 4 sky panels installed, with the Ibar installed. If any sky panel appears to be not square in the opening or sitting high –
verify the dimensions and adjust as necessary following SI DOC ID 6339878 (pickup) or
6341146 (SUV)

6542346
6542288

Verify the dimensions and adjust as necessary
following SI DOC ID 6339878 (pickup), 6341146 (SUV).

6542318

Page 6

July, 2024

Bulletin No.: 24-NA-029

Condition

Water dripping into the cabin from between the sky panel and its seal (front corner of the
LR panel pictured), especially when stopping.

Cause/Correction

This was due to the left rear sky panel being too far rearward allowing poor seal along the
front edge of the left rear sky panel to weather strip. Essentially overwhelming the water
drain management system. To adjust the sky panel, refer to SI DOC ID 6339878 (pickup)
or 6341146 (SUV).

6542378
6542375

Condition

Water drains into the cabin from between the sky panel and its seal (front corner of the
RF panel pictured).

Cause/Correction

Adjusting the sky panel strikers down resolved the leak. To adjust the sky panel strikers,
refer to SI DOC ID 6339878 (pickup) or 6341146 (SUV).

6542379

Bulletin No.: 24-NA-029

July, 2024

Page 7

Condition

Water leaking past the top of the window, and onto the door trim panel.

Cause

Sky panel weather strip was not properly seated to the metal u-channel. The weather
strip will have an uneven appearance on the end. Further inspection should reveal the
weather strip is not properly seated onto and under the metal u-channel. Water will leak
at the overlap joint between the sky panel weather strip and roof bow weather strip.

Correction

Inspect the sky panel weather strip to ensure it’s properly seated onto the metal u-channel retainer. If necessary, pull the weather strip up and away, then gently re-seat the
weather strip over the u-channel. Verify the weather strip lays flat on the ends.

Side Window Water Leaks

6542380

Condition

Water leaks between the side windows and weather strips.

Cause

Side glass is out of position, including being too low or tilted at an angle, the glass will not
seal properly to the door opening weather strips or the top weather strip on the sky panel.

Correction

Inspect the side door glass ensuring it’s square in the body opening and covering the
weather strip evenly on both sides. Compare the height and orientation from side to
side. Adjustments are made by loosening the window regulator to door glass clamps.
Refer to applicable SI procedure for regulator replacement for proper steps to access
these attachment points.
Note: Side Glass out of adjustment can also cause wind noise.

Page 8

July, 2024

Bulletin No.: 24-NA-029

6542381

Condition

Water leaks between the side windows and weather strips.

Cause

Side glass out of position, including being tilted outboards causing a lack of pressure
between the side glass and the weather strip.

Correction

Inspect the side door glass ensuring that it’s compressing onto the door opening weather
strips. Tilting the glass inwards will help push the glass onto the door opening weather
strips making a tighter seal. Adjustments are made by loosing the window regulator to
door bottom mounting bolt and tilting the entire window and regulator asm as needed.
Refer to applicable SI procedure for regulator replacement for proper steps to access
these attachment points.

6542383

Bulletin No.: 24-NA-029

July, 2024

Page 9

Condition

Water leaks between the side windows and weather strips

Cause

Plugged drain(s)

Correction

Inspect the drain hole closest to the location where the leak is occurring. Look for any
rubber flashing that might be partially covering the drain hole(s). Remove debris or rubber
flashing as required.
Tip: With the top removed, close the door, fully raise the window check the drain hole to
ensure it’s not being pinched closed when the side window is all the way up.

6542384

Condition

Water leaks between the side windows and weather strips

Cause

Plugged drain(s)

Correction

Inspect the drain hole closest to the location where the leak is occurring. Look for any
debris or rubber flashing that might be partially covering the drain hole(s). Remove flashing if required.
Tip: With the top removed, close the door, fully raise the window check the drain hole to
ensure it’s not being pinched closed when the side window is all the way up.

Version

2

Modified

Released February 08, 2024
Revised July 11, 2024 – Added 2025 Model Year.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job
properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.

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