BULLETIN NOTES
APPLICABLE MODEL(S)/VINS
2019-2026 Mazda3 4-Door (Japan built)

DESCRIPTION
Some customers may notice water in the trunk after a car wash or heavy rain.This may be caused by insufficient sealing
performance of the trunk lid weatherstrip. Due to improper installation of weatherstrips, the lip of the weatherstrip may
lean toward the inside of the trunk, resulting in insufficient sealing performance.
Customers having this concern should have their vehicle repaired using the following repair procedure.

REPAIR PROCEDURE
1. Verify customer concern.
NOTE: Inspect for proper trunk lid alignment before proceeding with the repair. If the trunk lid is mis-aligned, it may be
causing the water leak and replacing the weatherstrip may not resolve the problem. If trunk lid alignment is ok, proceed
to next step.
2. Is the lip of the trunk lid weatherstrip tilted inward as shown in the image below?
- If Yes, proceed to Step 3.
- If No, the cause of water leak is not applicable to this Service Information.

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Weatherstrip area tilted inward
3. Replace the trunk lid weatherstrip with a new one according to the following procedures.
NOTE: For details for steps b - e below, refer to the instructions on MGSS TRUNK LID WEATHERSTRIP
INSTALLATION (steps 1 - 4).
a. Remove the trunk lid weatherstrip.
b. Clean along the entire perimeter of the body panel flange.
c. Align the trunk lid weatherstrip marking with the body panel marking and install (A) of the trunk lid weatherstrip.
d. Align the contact point of the trunk lid weatherstrip with the trunk lid lock striker and install (D) (refer to the MGSS) of
the trunk lid weatherstrip.
e. Install the trunk lid weatherstrip (1) from (D) in the directions of the arrows shown below.

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Trunk Lid Weatherstrip Installation Note
Location
D
Straight area immediately after D
(both left and right)
Corner area of D-B and D-C
B-A and C-A

Installation Note
Starting point of weatherstrip (1) installation.
Install the weatherstrip with slight tension.
Install the weatherstrip from bottom to top, gathering the c
orner sections towards the center of the corner.
Install the weatherstrip without stretching it.

f. Press in the trunk lid weatherstrip at the corner areas (yellow arrows) again.
NOTE: Refer to MGSS "Trunk Lid Weatherstrip Installation Note" and pay special attention to the Note when installing
the corner sections.

4. Measure the height of the trunk lid weather strip according to steps a - c (below).
NOTE: The images below show the right side. The left side is symmetrical.
a. Create an L-shaped gauge (shown below) to measure the height of the weatherstrip using thick paper or similar
material.

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L-shaped gauge: 24mm {0.95 in.}
NOTE: Other L-shaped gauge dimensions are not specified; create as needed.
b. Place the L-shaped gauge at the center of the corner (yellow frame area) so that it contacts to the edge of the
combination lamp as shown below.

View from the vehicle rear

View from the the trunk room inside

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(1) Location to place the gauge:
Edge of the rear combination lamp.

View from above the vehicle
c. Check for the gap between the gauge (1) and the weatherstrip (2) below.
Does the top of the weatherstrip contact to the bottom of the gauge?
- If Yes, go to Step 5.
- If No, remove the weatherstrip and reinstall it properly.

GOOD: The top of the weatherstrip contacts the gauge.
(1) L-shaped gauge
(2) Trunk Lid Weatherstrip
(3) Body Panel
5. Check for water intrusion in the trunk according to the following procedures. If water intrusion is detected, remove the
trunk lid weatherstrip and reinstall it properly.
a. Spray water for 20-30 seconds on each side from a distance of 100 mm {4 in.} in front of both sides of the front edge
of the trunk lid as shown below, ensuring that all the water enters the parting gap.
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►Water spraying conditions
• Water Flow Rate: The table below or 25.5 liters / min.
1

Hose Inner Diameter

14 - 16 mm {0.55 - 0.63 in.}

2

Water Head when facing vertically up
ward

270 - 330 mm {10.6 - 13.0 in.}
(height of 950 - 1050 mm {37.4 - 41.3 i
n.} above the ground)

• Water Spraying Distance (3): 90 - 110 mm {3.5 - 4.3 in. }

PARTS INFORMATION
Parts Number

Description

Q'ty

Notes

BCKA-56-951A

Weatherstrip

1

Even if the old part numbers
(BCJH-56-951*) can be use
d.

WARRANTY INFORMATION
NOTE:
• This warranty information applies only to verified customer complaints on vehicles eligible for warranty repair.
• This repair will be covered under Mazda’s New Vehicle Limited Warranty term.
• Additional diagnostic time cannot be claimed for this repair.
Warranty Type

A

Symptom Code

77
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Damage Code
Causal Part No.
Quantity
Operation No. and Labor Hours

9B
BCKA-56-951A
1
XXX3AXRX / 0.5 Hrs.

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