Bulletin No.: PIT5396D
Published date: 03/18/2020

Preliminary Information
PIT5396D Diagnostic Tips - Water Leaks
Models
Brand:

Model:

Model Years:

VIN:
from

Engine:

to

Transmissions:

Chevrolet

Colorado

2015 - 2020

All

All

All

All

GMC

Canyon

2015 - 2020

All

All

All

All

Supersession Statement
This PI was superseded to update Recommendation/Instructions. Please discard PIT5396C.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition / Concern
A customer or dealer Technician may comment of a water leak into the cab of the truck,
Water staining may be seen in the headliner or water may be on the floor.

Recommendations / Instructions
To assist with water leak issues on these models, it is recommended to follow the procedure
in SI for Water Leak Diagnosis and inspect the following areas:
1)
Roof ditch: May exhibit sealer skips causing water in various areas of the vehicle. Pin
holes in the roof ditch sealer at front and rear will allow water intrusion in the respective
areas. Front will run behind the A-Pillar trim, along the edge of the IP and drip/splash on the
kick panel. The rear will enter on the inside of the glass very close to the roof ditch seam.
A void along the seam can enter in either the front or the rear.
2)
Rear glass: May exhibit sealer skip or be improperly seated causing headliners to be
stained. Back glass sealer voids can be caused by hand installing the back glass, usually
there are urethane smear signs on the body. If the glass locating pins are not seated in the
locating hole, the glass could be out of position allowing a leak point near the dislocated pin.
3)
CHMSL: May allow water to travel along the rear header to roof flange and can enter
the vehicle anywhere along the back glass, appearing to be a back glass leak.
4)
Windshield: May allow water to accumulate on the front floor. If the windshield is not
located properly the locating pin could slide below the locating hole, allowing the windshield
to set low. Tip: When the windshield is low the VIN plate is covered.
5)
Cowl seam: May allow water to accumulate on the floor. Water test by cowl drain left
and right side. Water may enter from outside cowl area under hood from left and right side
add seam sealer.

The other area is under dash in the left and right side vertical seams. Reseal as needed

6)
HVAC drain tube: May soak the front floor area on either side if the drain tube is
dislocated. It could appear to be a dash area leak. More likely to be reported during A/C
operation in high humidity conditions.
7)
A Pillar area: May exhibit missing sealer at the door hinges. Inspect for a weld
through condition along the outer pillar/bulkhead to fender support that leads straight to the
inside of the front bulkhead. There are also three welds on the top of the pillar/bulkhead for
the fender bracket. The baffles hold the water in the pillar/bulkhead where it pools while
seeping into the cab through the harness rosebud holes. Also inspect for issues with the
pillar plug or the door boot not being seated.
8)
PRV (Pressure Relief Valve): May not be fully seated. Water runs along the back panel
and down to the front foot area.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.

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