Water Leak in Front Floor Carpet Area - body case cowl housing odor

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Some customers may come to the dealer with an issue of mildew odor or wet carpet in the front passenger seat area.

The three most common causes for this issue result from:

A) Water backing up at the plenum drain

B) Voids in the plenum seam sealer, or

C) The HVAC recirculation door being left open

D) Door harness boot

E) Plenum/Cowl/Instrument sub panel - sometimes referred to as windshield tray

A) Too much sealer at the plenum drain area can act as a dam, allowing water to back up in the plenum and either seep around the air box seal, or around the lower right air box mounting screw. If a plenum drain has a ridge of sealer higher than 1/4 inch, use a utility knife to cut the sealer down to 1/4 inch in height.

A) Too much sealer at the plenum drain area can act as a dam, allowing water to back up in the plenum and either seep around the air box seal, or around the lower right air box mounting screw. If a plenum drain has a ridge of sealer higher than 1/4 inch, use a utility knife to cut the sealer down to 1/4 inch in height.

B) A mirror can be used to examine the inside of the plenum for possible voids in the seam sealer where water can gain entry to the passenger compartment. Seal any voids using the procedures listed in your service manual.

C) The HVAC recirculation, or air box, door opens upward when the HVAC conrols are set to Max A/C. In extreme conditions, water can pool on top of this door and spill into the vehicle. This door can remain open if the HVAC mode is set to Max A/C when the ignition key is cycled off. Customers should be informed of this condition and should be advised to turn the HVAC setting to the regular A/C or OFF position before turning the vehicle off.

D) Water that is found in either the driver or passenger floor at the 'A' pillar may have entered at the door harness boot on the 'A' pillar side. Make sure the boot harness if fully seated in the 'A' pillar.

E) Water may enter at the three piece Plenum/Cowl/Instrument sub panel. This area must be sealed from the inside of the vehicle, which will need the dash assembly removed to gain access. This area can be sealed by spraying a clear sealer (KENT is the brand) in a gallon commercial sprayer, up under the Plenum/Cowl/Instrument sub panel.

Please follow this diagnosis 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. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.